Liquid-crystalline medium

ABSTRACT

The invention relates to a liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, characterized in that it contains one or more compounds of the general formula I ##STR1## in which X is fluorine, chlorine, CF 3 , OCF 3  or OCHF 2 , ring A is trans-1,4-cyclohexylene or 1,4-phenylene, and R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms.

This application is a continuation of application Ser. No. 07/781,151, filed Oct. 31, 1991, abandoned which is based on international application PCT/EP91/01337, filed Jul. 16, 1991 abandoned.

The present invention relates to a liquid-crystalline medium, to the use thereof for electrooptical purposes, and to displays containing this medium.

The main use of liquid crystals is as dielectrics in display devices since the optical properties of such substances can be affected by an applied voltage. Electrooptical devices based on liquid crystals are extremely well known to persons skilled in the art and may be based on various effects. Examples of devices of this type are cells having dynamic scattering, DAP cells (deformation of aligned phases), guest/host cells, TN cells having a twisted nematic structure, STN cells ("supertwisted nematic"), SBE cells ("super-birefringence effect") and OMI cells ("optical mode interference"). The most common display devices are based on the Schadt-Helfrich effect and have a twisted nematic structure.

The liquid-crystal materials must have good chemical and thermal stability and good stability towards electrical fields and electromagnetic radiation. Furthermore, the liquid-crystal materials should have low viscosity and give short addressing times, low threshold voltages and high contrast in the cells. Furthermore, at customary operating temperatures, i.e., in the broadest possible range above and below room temperature, they should have a suitable mesophase, for example a nematic or cholesteric mesophase for the abovementioned cells. Since liquid crystals are generally used as mixtures of a plurality of components, it is important that the components are readily miscible with one another. Further properties, such as the electrical conductivity, dielectric anisotropy and optical anisotropy, must meet various requirements depending on the cell type and the area of application. For example, materials for cells having a twisted nematic structure should have positive dielectric anisotropy and low electrical conductivity.

For example, the media desired for matrix liquid-crystal displays containing integrated nonlinear elements for switching individual image points (MLC displays) are those having high positive dielectric anisotropy, broad nematic phases, relatively low birefringence, very high specific resistance, good UV and temperature stability of the resistance and low vapor pressure.

Matrix liquid-crystal displays of this type are known. Examples of nonlinear elements which can be used to individually switch the individual image points are active elements (i.e., transistors). This is then referred to as an "active matrix", and a differentiation can be made between two types:

1. MOS (metal oxide semiconductor) transistors on a silicon wafer as substrate.

2. Thin-film transistors (TFTs) on a glass plate as substrate.

The use of monocrystalline silicon as a substrate material limits the display size since even the modular assembly of the various part displays results in problems at the joints.

In the case of the more promising type 2, which is preferred, the electrooptical effect used is usually the TN effect. A differentiation is made between two technologies: TFTs comprising compound semiconductors, such as for example, CdSe, or TFTs based on polycrystalline or amorphous silicon. Intensive research efforts are being made worldwide in the latter technology.

The TFT matrix is applied to the inside of one glass plate of the display, while the inside of the other glass plate carries the transparent counterelectrode. Compared with the size of the image point electrode, the TFT is very small and has virtually no adverse effect on the image. This technology can also be extended to fully color-compatible image displays, in which a mosaic of red, green and blue filters is arranged in such a manner that each filter element is located opposite a switchable image element.

The TFT displays usually operate as TN cells with crossed polarizers in transmission and are illuminated from the back.

The term MLC display here covers any matrix display containing integrated nonlinear elements, i.e., in addition to the active matrix, also displays containing passive elements such as varistors or diodes (MIM=metal-insulator-metal).

MLC displays of this type are particularly suitable for TV applications (for example pocket TV sets) or for high-information displays for computer applications (laptops) and in automobile or aircraft construction. In addition to problems with respect to the angle dependence of the contrast and the response times, problems result in MLC displays due to inadequate specific resistance of the liquid-crystal mixtures [TOGASHI, S., SEKIGUCHI, K., TANABE, H., YAMAMOTO, E., SORIMACHI, K., TAJIMA, E., WATANABE, H., SHIMIZU, H., Proc. Eurodisplay 84, Sept. 1984: A 210-288 Matrix LCD Controlled by Double Stage Diode Rings, p. 141 ff, Paris; STROMER, M., Proc. Eurodisplay 84, Sept. 1984: Design of Thin Film Transistors for Matrix Adressing of Television Liquid Crystal Displays, p. 145 ff, Paris]. As the resistance decreases, the contrast of an MLC display worsens and the problem of "after image elimination" may occur. Since the specific resistance of liquid crystal mixture generally decreases over the life of an MLC display due to interaction with the internal surfaces of the display, a high (initial) resistance is very important to give acceptable service lives. In particular in the case of low-voltage mixtures, it was hitherto not possible to achieve very high specific resistances. It is furthermore important that the specific resistance increases as little as possible with increasing temperature and after heating and/or exposure to UV radiation. In addition, certain applications require very low birefringence and other applications require high birefringence, low threshold voltages, relatively high surface tilt angles in order to avoid "reversed tilt" domains, low viscosity, broad nematic mesophases and good low-temperature stability. The MLC displays of the prior art thus do not satisfy current demands.

It has hitherto been possible to prepare liquid-crystalline media having birefringence and phase range values necessary for practical use (for example clearing point of ≧70°) and having threshold voltages of about 1.8 volts if values of about 98% for the holding ratio under extreme conditions (for example after UV exposure) are desired.

Thus, there continues to be a great demand for MLC displays having very high specific resistance and at the same time a broad operating temperature range, short response times and low threshold voltage which do not have these disadvantages or only do so to a lesser extent.

For TN (Schadt-Helfrich) cells, media are desired which facilitate the following advantages in the cells:

broadened nematic phase range (in particular down to low temperatures),

switchability at extremely low temperatures (outdoor use, automobiles, avionics),

increased stability to UV radiation (longer life).

The media available from the prior art do not make it possible to achieve these advantages whilst simultaneously retaining the other parameters.

For supertwisted (STN) cells, media are desired which have a greater multiplexing ability and/or lower threshold voltages and/or broader nematic phase ranges (in particular at low temperatures). To this end, a further extension of the parameter latitude available (clearing point, smectic-nematic transition or melting point, viscosity, dielectric values, elastic values) is urgently desired.

The object of the invention is to provide media, in particular for MLC, TN or STN displays of this type, which do not have the abovementioned disadvantages or only do so to a lesser extent, and preferably simultaneously have very high specific resistances and low threshold voltages.

It has now been found that this object can be achieved if media according to the invention are used in displays.

The invention thus relates to a liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, characterized in that it contains one or more compounds of the general formula I ##STR2## in which X is fluorine, chlorine, CF₃, OCF₃ or OCHF₂, ring A is-trans-1,4-cyclohexylene or 1,4-phenylene, and R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms.

The invention also relates to electrooptical displays (in particular STN or MLC displays having two plane-parallel outer plates which, together with a frame, form a cell, integrated nonlinear elements for switching individual image points on the outer plates, and a nematic liquid-crystal mixture of positive dielectric anisotropy and high specific resistance located in the cell) which contains media of this type, and to the use of these media for electrooptical purposes.

The liquid-crystal mixtures according to the invention facilitate a significant broadening of the parameter latitude available.

The media according to the invention are based on a mixture of polar compounds. These are preferably not highly polar compounds such as the known nitriles, but instead medium-polarity compounds having a rod-like structure containing two, three or four six-membered carbo- or heterocyclic rings which are linked to one another in the 1,4-position either directly or via divalent bridging members and are linked terminally to two wing groups. One of these wing groups is a nonpolar group such as, for example, alkyl, alkoxy, oxaalkyl, dioxaalkyl, alkenyl, fluoroalkyl or fluoroalkenyl, and the other wing group is a halogenated medium-polarity group, such as, for example, fluorine, chlorine, difluoroalkyl, higher fluorinated alkyl, alkoxy, alkenyl, alkenyloxy or alkanoyloxy.

The compounds of the formula I are representatives of this group of medium-polarity compounds, whose ring structures may also be laterally substituted by halogen, preferably fluorine.

The achievable combinations of clearing point, birefringence, viscosity at low temperature, thermal and UV stability and dielectric anisotropy are far superior to the previous materials from the prior art.

The requirement for a high clearing point, a nematic phase at -40° C. and a high Δε was previously only achievable to an unsatisfactory extent. Although systems such as, for example, ZLI-3119 have a comparable clearing point and comparatively favorable viscosities, they have, however, a Δε of only +3.

Other mixture systems have comparable viscosities and values of Δε, but only have clearing points in the region of 60° C.

The liquid-crystal mixtures according to the invention make it possible to simultaneously achieve low viscosities at low temperatures (≦600, preferably ≦550 mPa.S at -30° C.; ≦1,800, preferably ≦1,700 mPa.s at -40° C.) and dielectric anisotropy values of ≧3.5, preferably ≧4.0, clearing points above 65°, preferably above 70°, and a high value for the specific resistance, which allows excellent STN and MLC displays to be achieved.

It goes without saying that a suitable choice of components of the mixtures according to the invention also allows higher clearing points (for example above 90°) to be achieved at higher threshold voltage or lower clearing points to be achieved at lower threshold voltages while retaining the other advantageous properties. The MLC displays according to the invention preferably operate in the first transmission minimum of Gooch and Tarry [C. H. Gooch and H. A. Tarry, Electron. Lett. 10, 2-4, 1974; C. H. Gooch and H. A. Tarry, Appl. Phys., Vol. 8, 1575-1584, 1975]; in this case, a lower dielectric anisotropy in the second minimum is sufficient in addition to particularly favorable electrooptical properties, such as, for example, high gradient of the characteristic line and low angle dependence of the contrast (German Patent 30 22 818) at the same threshold voltage as in an analogous display. This allows significantly higher specific resistances to be achieved in the first minimum using the mixtures according to the invention than using mixtures containing cyano compounds. A person skilled in art can use simple routine methods to establish the birefringence necessary for a prespecified layer thickness of the MLC display through a suitable choice of the individual components and their proportions by weight.

The viscosity at 20° C. is preferably ≦18 mPa.s, in particular ≦15 mPa.s.

The nematic phase range is preferably at least 70°, in particular at least 80°. This range preferably extends at least from -30° to +85°.

Measurements of the "capacity holding ratio" (HR) [S. Matsumoto et al., Liquid Crystals 5, 1320 (1989); K. Niwa et al., Proc. SID Conference, San Francisco, June 1984, p. 304 (1984); G. Weber et al., Liquid Crystals 5, 1381 (1989)] have shown that mixtures according to the invention containing compounds of the formula I exhibit a considerably smaller decrease in the HR with increasing temperature than do analogous mixtures in which the compounds of the formula I are replaced by cyanophenyl-cyclohexanes of the formula ##STR3## The UV stability of the mixtures according to the invention is also considerably better, i.e. they exhibit a significantly smaller decrease in the HR on exposure to UV radiation.

The threshold voltages V_(10/0/20) achieved are generally ≦1.6 volts and preferably in the range from 1.4 to 1.6 volts.

The media according to the invention are distinguished by extremely favorable elastic constants and very favorable viscosity values in addition to an unusually broad nematic phase range, resulting, in particular when used in TFT displays, in significant advantages over prior-art media.

The media according to the invention are preferably based on a plurality (preferably two or more) compounds of the formula I, i.e. the proportion of these compounds is ≧25%, preferably ≧40%.

The individual compounds of the formulae I to XII and their subformulae which can be used in the media according to the invention are either known or can be prepared analogously to the known compounds.

Preferred embodiments are given below:

The medium additionally contains one or more compounds selected from the group comprising the general formulae II, III and IV: ##STR4## in which the individual radicals have the following meanings: R: alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms

Q: --C₂ H₄ --, --C₄ H₈ -- or --CO--O,

X: F, Cl, CF₃, OCF₃ or OCHF₂

Y: H or F

A: trans-1,4-cyclohexylene or 1,4-phenylene

r: 0 or 1.

The medium contains one or more compounds of the formula II and/or III in which r is 0:

The medium contains one or more compounds selected from the group comprising the general formulae V and VI: ##STR5## in which R is as defined above, and Z is --C₂ H₄ --, --CO--O-- or --O--CO--.

The medium additionally contains one or more compounds selected from the group comprising the general formulae VII to XII: ##STR6## in which R, r, X and Y are each, independently of one another, as defined above.

The proportion of compounds of the formulae I to IV together in the total mixture is at least 50% by weight

The proportion of compounds of the formula I in the total mixture is from 10 to 50% by weight

The proportion of compounds of the formulae II to IV in the total mixture is from 30 to 70% by weight ##STR7## The medium contains compounds of the formulae II and III or IV R is straight-chain alkyl or alkenyl having 2 to 7 carbon atoms

The medium essentially comprises compounds of the formulae I to IV

The medium contains further compounds, preferably selected from the following group: ##STR8## The I:(II+III+IV) ratio by weight is preferably from 1:4 to 1:1. The medium essentially comprises compounds selected from the group comprising the general formulae I to XII.

It has been found that even a relatively a small proportion of compounds of the formula I mixed with conventional liquid-crystal materials, but in particular containing one or more compounds of the formula II, III and/or IV, results in a significant improvement in the addressing times and in lower threshold voltages, and at the same time broad nematic phases with low smectic-nematic transition temperatures are observed. The compounds of the formulae I to IV are colorless, stable and readily miscible with one another and with other liquid-crystal materials.

Depending on the choice of specific compounds of the formula I or combinations of a plurality of types of compounds of the formula I, the compounds according to the invention can be decisively improved for various requirements. The table below shows the effect of various compounds of the formula I on selected, important parameters, an increasing number of + signs indicating an increasingly positive effect, 0 indicating an indifferent effect and - denoting an impairment of the parameter indicated. Since it is always necessary to make compromises when improving LC media, however, even compounds with "-" for one parameter are extremely helpful in developing the mixture if their concentration is chosen appropriately.

Preferred media simultaneously contain compounds of the formula A ##STR9## in which R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms; r is 0 or 1; X is F, Cl, CF₃, OCF₃ or OCHF₂ ; and Y is H or F.

r is preferably 0. X is preferably F, Cl, OCF₃ or OCHF₂. The following combinations of X and Y are particularly preferred:

    ______________________________________                                         Y           X            Y                                                     ______________________________________                                         F           F            H     (a)                                             H           OCF.sub.3    H     (b)                                             F           OCF.sub.3    H     (c)                                             F           OCHF.sub.2   H     (d)                                             ______________________________________                                    

Particular preference is given to combinations of the compounds of the formula I where A=cyclohexylene and X=OCHF₂ with A (a) due to the particularly low birefringence and simultaneously low threshold voltage. Similarly advantageous are A (b) with compounds I where A=cyclohexylene and X=CF₃.

The preferred compounds of the formula A ##STR10## are denoted by the acronym CUP-nX(.F):

    __________________________________________________________________________                                  Birefringence                                     Formula I         Nematic    low                                                                               high     Low-temp.                             A   X    Acronym  phase                                                                               Threshold                                                                            Δn                                                                          Δn                                                                           Viscosity                                                                           stability                             __________________________________________________________________________     Cy  F    CCP-nF.F.F                                                                              +    +     ++     +    +                                     Ph  F    BCH-nF.F.F                                                                              ++   ++    +      ++   +                                     Cy  Cl   CCP-nCl.F.F                                                                             ++   +     +      0    ++                                    Ph  Cl   BCH-nCl.F.F                                                                             ++   ++       ++  0    0                                     Cy  CF.sub.3                                                                            CCP-nCF.sub.3.F.F                                                                       0    ++    ++     +    -                                     Ph  CF.sub.3                                                                            BCH-nCF.sub.3.F.F                                                                       +    ++    0  0   +    -                                     Cy  OCHF.sub.2                                                                          CCP-nOCF.sub.2.F.F                                                                      ++   +     ++     ++   ++                                    Ph  OCHF.sub.2                                                                          BCH-nOCF.sub.2.F.F                                                                      ++   ++    0      +    ++                                    Cy  OCF.sub.3                                                                           CCP-nOCF.sub.3.F.F                                                                      ++   ++    ++     0    ++                                    Ph  OCF.sub.3                                                                           BCH-nOCF.sub.3.F.F                                                                      ++   ++    +      0    ++                                    Formula A                                                                      (r = 0) R = C.sub.n H.sub.2n+1                                                 X   Y  Y                                                                       F   F  H CUP-nF.F +    ++    ++     0    +                                     OCF.sub.3                                                                          H  H CUP-nOCF.sub.3                                                                          0    +     +      0    +                                     OCF.sub.3                                                                          F  H CUP-nOCF.sub.3.F                                                                        ++   +++   ++     -    ++                                    __________________________________________________________________________

The term "alkyl" includes straight-chain and branched alkyl groups having 1-7 carbon atoms, in particular the straight-chain groups methyl, ethyl, propyl, butyl, pentyl, hexyl and heptyl. Groups having 2-5 carbon atoms are generally preferred.

The term "alkenyl" includes straight-chain and branched alkenyl groups having 2-7 carbon atoms, in particular the straight-chain groups. Particular alkenyl groups are C₂ -C₇ -1E-alkenyl, C₄ -C₇ -3E-alkenyl, C₅ -C₇ -4-alkenyl, C₆ -C₇ -5-alkenyl and C₇ -6-alkenyl, in particular C₂ -C₇ -1E-alkenyl, C₄ -C₇ -3E-alkenyl and C₅ -C₇ -4-alkenyl. Examples of preferred alkenyl groups are vinyl, 1E-propenyl, 1E-butenyl, 1E-pentenyl, 1E-hexenyl, 1E-heptenyl, 3-butenyl, 3E-pentenyl, 3E-hexenyl, 3E-heptenyl, 4-pentenyl, 4Z-hexenyl, 4E-hexenyl, 4Z-heptenyl, 5-hexenyl, 6-heptenyl and the like. Groups having up to 5 carbon atoms are generally preferred.

The term "fluoroalkyl" preferably includes straight-chain groups containing terminal fluorine, i.e. fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl and 7-fluoroheptyl. However, other positions of the fluorine are not excluded.

The term "oxaalkyl" preferably includes straight-chain radicals of the formula C_(n) H_(2n+1) --O--(CH₂)_(m) in which n and m are each, independently of one another, 1 to 6 or m is alternatively 0. n is preferably 1 and m is preferably from 1 to 6.

Through a suitable choice of the meanings of R, A, X and Y, the addressing times, the threshold voltage, the gradient of the transmission characteristic lines, etc., can be modified as desired. For example, 1E-alkenyl radicals, 3E-alkenyl radicals, 2E-alkenyloxyradicals and the like generally give shorter addressing times, improved nematic tendencies and a higher ratio between the elastic constants k₃₃ (bend) and k₁₁ (splay) compared with alkyl and alkoxy radicals. 4-Alkenyl radicals, 3-alkenyl radicals and the like generally give lower threshold voltages and lower values of k₃₃ /k₁₁ compared with alkyl and alkoxy radicals. A --CH₂ CH₂ -- group in Z¹ or Z² generally results in higher values of k₃₃ /k₁₁ compared with a simple covalent bond. Higher values of k₃₃ /k₁₁ facilitate, for example, flatter transmission characteristic lines in TN cells with a 90° twist (for achieving gray tones) and steeper transmission characteristic lines in STN, SBE and OMI cells (greater multiplexing ability), and vice versa.

The optimum mixing ratio of the compounds of the formulae I and II+III+IV depends substantially on the desired properties, on the choice of the components of the formulae I, II, III and/or IV and on the choice of any other components which may be present. Suitable mixing ratios within the abovementioned range can easily be determined from case to case.

The total amount of compounds of the formulae I to XII in the mixtures according to the invention is not crucial. The mixtures may therefore contain one or more further components in order to optimize various properties. However, the observed effect on the addressing times and the threshold voltage is generally greater the higher the total concentration of compounds of the formulae I to XII.

In a particularly preferred embodiment, the media according to the invention contain compounds of the formula II, III, V and/or VII (preferably II and/or III) in which X is CF₃, OCF₃ or OCHF₂. A favorable synergistic effect with the compounds of the formula I results in particularly advantageous properties.

For STN applications, the media preferably contain compounds selected from the group comprising the formulae V to VIII in which X is preferably OCHF₂.

The media according to the invention may furthermore contain a component A comprising one or more compounds of the general formula I' having a dielectric anisotropy of -1.5 to +1.5 ##STR11## in which R¹ and R² are each, independently of one another, n-alkyl, ω-fluoroalkyl or n-alkenyl having up to 9 carbon atoms,

the rings A¹, A² and A³ are each, independently of one another, 1,4-phenylene, 2- or 3-fluoro-1,4-phenylene, trans-1,4-cyclohexylene or 1,4-cyclohexenylene,

Z¹ and Z² are each, independently of one another, --CH₂ CH₂ --, C═C--, --CO--O--, --O--CO--, or a single bond,

and

m is 0, 1 or 2.

Component A preferably contains one or more compounds selected from the group comprising II1 to II7: ##STR12## in which R¹ and R² are as defined under the formula I'.

Component A preferably additionally contains one or more compounds selected from the group comprising II8 to II20: ##STR13## in which R¹ and R² are as defined under the formula I', and the 1,4-phenylene groups in II8 to II17 may each, independently of one another, also be monosubstituted or polysubstituted by fluorine.

Furthermore, component A preferably additionally contains one or more compounds selected from the group comprising II21 to II25: ##STR14## in which R¹ and R² are as defined under the formula I' and the 1,4-phenylene groups in II21 to II25 may each, independently of one another, also be monosubstituted or polysubstituted by fluorine.

Finally, preferred mixtures of this type are those in which component A contains one or more compounds selected from the group comprising II26 and II27: ##STR15## in which C_(t) H_(2t+1) is a straight-chain alkyl group having up to 7 carbon atoms.

In some cases, the addition of compounds of the formula ##STR16## in which R¹ and R² are as defined under the formula I'

and ##STR17## proves advantageous for suppressing smectic phases, although this may reduce the specific resistance. In order to achieve parameter combinations which are ideal for the application, a person skilled in the art can easily determine whether and, if yes, in what amount these compounds may be added. Normally, less than 15%, in particular 5-10%, are used.

Preference is also given to liquid-crystal mixtures which contain one or more compounds selected from the group comprising III' and IV': ##STR18## in which R¹ and R² are as defined under the formula I'.

The type and amount of the polar compounds having positive dielectric anisotropy is not crucial per se. A person skilled in the art can use simple routine experiments to select suitable materials form a wide range of known and, in many cases, also commercially available components and base mixtures. The media according to the invention preferably contain one or more compounds of the formula I" ##STR19## in which Z¹, Z² and m are as defined under the formula I', Q¹ and Q² are each, independently of one another, 1,4-phenylene, trans-1,4-cyclohexylene or 3-fluoro-1,4-phenylene, or one of the radicals Q¹ and Q² is alternatively trans-1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl or 1,4-cyclohexenylene.

R⁰ is n-alkyl, n-alkenyl, n-alkoxyor n-oxaalkyl, in each case having up to 9 carbon atoms, Y is H or F and X' is CN, halogen, CF₃, OCF₃ or OCHF₂.

In a preferred embodiment, the media according to the invention for STN or TN applications are based on compounds of the formula I" in which X' is CN. It goes without saying that smaller or larger proportions of other compounds of the formula I" (X'≠CN) are also possible. For MLC applications, the media according to the invention preferably contain only up to about 10% of nitriles of the formula I" (but preferably no nitriles of the formula I", but instead compounds of the formula I' where X' is halogen, CF₃, OCF₃ or OCHF₂). These media are preferably based on the compounds of the formulae II to XII.

The construction of the STN and MLC displays according to the invention from polarizers, electrode base plates and electrodes with surface treatment corresponds to the construction which is conventional for displays of this type. The term conventional construction here is widely drawn and also covers all derivatives and modifications of the MLC display, in particular also matrix display elements based on poly-Si TFTs or MIMs.

An essential difference between the displays according to the invention and those customary hitherto based on the twisted nematic cell is, however, the choice of liquid-crystal parameters in the liquid-crystal layer.

The liquid-crystal mixtures which can be used according to the invention are prepared in a manner which is conventional per se. In general, the desired amount of the components used in a lesser amount is dissolved in the components making up the principal constituent, expediently at elevated temperature. It is also possible to mix solutions of the components in an organic solvent, for example acetone, chloroform or methanol, and, after thorough mixing, to remove the solvent again, for example by distillation.

The dielectrics may also contain other additives known to those skilled in the art and described in the literature. For example, 0-15% of pleochroic dyes or chiral dopes can be added. C denotes a crystalline phase, S a smectic phase, S_(B) a smectic B phase, N a nematic phase and I the isotropic phase.

V₁₀ denotes the voltage for 10% transmission (viewing direction perpendicular to the plate surface). t_(on) denotes the switch-on time and t_(off) the switch-off time at an operating voltage corresponding to 2.5 times the value of V₁₀. An denotes the optical anisotropy and n_(o) the refractive index. Δε denotes the dielectric anisotropy (Δε=ε.sub.∥ -ε.sub.⊥, where ε.sub.∥ is the dielectric constant parallel to the longitudinal molecular axes and ε.sub.⊥ is the dielectric constant perpendicular thereto. The electrooptical data were measured in a TN cell in the 1st minimum (i.e. at a d.Δn value of 0.4μ) at 20° C., unless expressly stated otherwise. The optical data were measured at 20° C., unless expressly stated otherwise.

The examples below are intended to illustrate the invention, but do not represent a limitation. Above and below, all temperatures are given in °C. The percentages are percent by weight.

In the present application and in the examples below, the structures of the liquid-crystal compounds are indicated by acronyms, with the transformation into chemical formulae taking place in accordance with Tables A and B below. All radicals C_(n) H_(2n+1) and C_(m) H_(2m+1) are straight-chain alkyl radicals containing n or m carbon atoms respectively. The coding in Table B is self evident. In Table A, only the acronym for the base structure is given. In individual cases, the acronym for the base structure is followed, separated by a hyphen, by a code for the substituents R¹, R², L¹ and L² :

    ______________________________________                                         Code for                                                                       R.sup.1,                                                                       R.sup.2, L.sup.1,                                                              L.sup.2                                                                               R.sup.1           R.sup.2     L.sup.1                                                                            L.sup.2                               ______________________________________                                         nm     C.sub.n H.sub.2n+1                                                                               C.sub.m H.sub.2m+1                                                                         H   H                                     nOm    C.sub.n H.sub.2n+1                                                                               OC.sub.m H.sub.2m+1                                                                        H   H                                     nO.m   OC.sub.n H.sub.2n+1                                                                              C.sub.m H.sub.2m+1                                                                         H   H                                     n      C.sub.n H.sub.2n+1                                                                               CN          H   H                                     nN.F   C.sub.n H.sub.2n+1                                                                               CN          H   F                                     nF     C.sub.n H.sub.2n+1                                                                               F           H   H                                     nOF    OC.sub.n H.sub.2n+1                                                                              F           H   H                                     nCl    C.sub.n H.sub.2n+1                                                                               Cl          H   H                                     nF.F   C.sub.n H.sub.2n+1                                                                               F           H   F                                     nOmFF  C.sub.n H.sub.2n+1                                                                               OC.sub.m H.sub.2m+1                                                                        F   F                                     nmF    C.sub.n H.sub.2n+1                                                                               C.sub.m H.sub.2m+1                                                                         F   H                                     nCF.sub.3                                                                             C.sub.n H.sub.2n+1                                                                               CF.sub.3    H   H                                     nOCF.sub.3                                                                            C.sub.n H.sub.2n+1                                                                               OCF.sub.3   H   H                                     nOCF.sub.2                                                                            C.sub.n H.sub.2n+1                                                                               OCHF.sub.2  H   H                                     nS     C.sub.n H.sub.2n+1                                                                               NCS         H   H                                     rVsN   C.sub.r H.sub.2r+1 --CH═CH--C.sub.s H.sub.2s --                                              CN          H   H                                     rEsN   C.sub.r H.sub.2r+1 --O--C.sub.s H.sub.2s --                                                      CN          H   H                                     nNF    C.sub.n H.sub.2n+1                                                                               CN          F   H                                     nAm    C.sub.n H.sub.2n+1                                                                               COOC.sub.m H.sub.2m+1                                                                      H   H                                     ______________________________________                                    

The compounds listed below are preferred components for media according to the invention, in particular those in which R² and/or X is F, Cl, CF₃, OCF₃ or OCHF₂.

                                      TABLE A                                      __________________________________________________________________________      ##STR20##                                                                                                   ##STR21##                                         ##STR22##                                                                                                   ##STR23##                                         ##STR24##                                                                                                   ##STR25##                                         ##STR26##                                                                                                   ##STR27##                                         ##STR28##                                                                                                   ##STR29##                                         ##STR30##                                                                                                   ##STR31##                                         ##STR32##                                                                                                   ##STR33##                                         ##STR34##                                                                                                   ##STR35##                                         ##STR36##                                                                                                   ##STR37##                                         ##STR38##                                                                                                   ##STR39##                                         ##STR40##                                                                                                   ##STR41##                                         ##STR42##                                                                                                   ##STR43##                                         ##STR44##                                                                                                   ##STR45##                                         ##STR46##                                                                                                   ##STR47##                                        __________________________________________________________________________

                                      TABLE B                                      __________________________________________________________________________      ##STR48##                                                                                                       ##STR49##                                     ##STR50##                                                                                                       ##STR51##                                     ##STR52##                                                                                                       ##STR53##                                     ##STR54##                                                                                                       ##STR55##                                     ##STR56##                                                                                                       ##STR57##                                     ##STR58##                                                                      ##STR59##                                                                      ##STR60##                                                                      ##STR61##                                                                                               ##STR62##                                             ##STR63##                                                                                                       ##STR64##                                     ##STR65##                                                                                                       ##STR66##                                     ##STR67##                                                                      ##STR68##                                                                                                       ##STR69##                                     ##STR70##                                                                                               ##STR71##                                             ##STR72##                                                                                               ##STR73##                                             ##STR74##                                                                                               ##STR75##                                             ##STR76##                                                                                               ##STR77##                                             ##STR78##                                                                                                       ##STR79##                                     ##STR80##                                                                                                       ##STR81##                                    __________________________________________________________________________

    ______________________________________                                         Example 1                                                                      PCH-5F     10.0%   S → N [°C.]                                                                    <-40                                          PCH-6F     7.0%    Clearing point [°C.]                                                                  +64                                           PCH-7F     15.0%   Viscosity 20° C.                                                                      4                                             CCP-20CF.sub.3                                                                            10.0%   Δn (589 nm, 20° C.)                                                             0.0800                                        CCP-30CF.sub.3                                                                            12.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5576                                        CCP-40CF.sub.3                                                                            8.0%    V.sub.(10,0,20)                                                                              1.61                                          CCP-50CF.sub.3                                                                            12.0%   V.sub.(50,0,20)                                                                              2.04                                          CCP-3F.F.F 10.0%   V.sub.(90,0,20)                                                                              2.66                                          BCH-5F.F   16.0%                                                               Example 2                                                                      PCH-5F     12.0%   S → N [°C.]                                                                    <-30                                          PCH-7F     8.0%    Clearing point [°C.]                                                                  +80                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0756                                       CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5489                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.66                                          ECP-3F.F   12.0%   V.sub.(50,0,20)                                                                              2.12                                          CCP-3F.F.F 14.0%   V.sub.(90,0,20)                                                                              2.73                                          CCP-3F.F.F 12.0%                                                               Example 3                                                                      PCH-5F     12.0%   S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +78                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      16                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0844                                        CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5610                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.61                                          BCH-3F.F   8.0%    V.sub.(50,0,20)                                                                              2.06                                          BCH-5F.F   6.0%    V.sub.(90,0,20)                                                                              2.72                                          CCP-3F.F.F 13.0%                                                               CCP-5F.F.F 12.0%                                                               Example 4                                                                      PCH-5F     12.0%   S → N [°C.]                                                                    --                                            PCH-7F     8.0%    Clearing point [°C.]                                                                  +77                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0847                                       CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5605                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.59                                          BCH-3F.F.F 14.0%   V.sub.(50,0,20)                                                                              --                                            ECCP-3F.F  12.0%   V.sub.(90,0,20)                                                                              --                                            CCP-5F.F.F 12.0%                                                               Example 5                                                                      PCH-5F     11.0%   S → N [°C.]                                                                    --                                            PCH-7F     9.0%    Clearing point [°C.]                                                                  +75                                           CCP-20CF.sub.3                                                                            8.0%    Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            10.0%   Δn (589 nm, 20° C.)                                                             0.0876                                        CCP-40CF.sub.3                                                                            7.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5666                                        CCP-50CF.sub.3                                                                            10.0%   V.sub.(10,0,20)                                                                              1.51                                          BCH-3F.F   10.0%   V.sub.(50,0,20)                                                                              1.95                                          BCH-5F.F   10.0%   V.sub.(90,0,20)                                                                              2.54                                          CCP-3F.F.F 13.0%                                                               CCP-5F.F.F 12.0%                                                               Example 6                                                                      PCH-5F     12.0%   S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +76                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0835                                        CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5595                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.49                                          BCH-3F.F.F 8.0%    V.sub.(50,0,20)                                                                              1.93                                          BCH-5F.F   6.0%    V.sub.(90,0,20)                                                                              2.52                                          CCP-3F.F.F 13.0%                                                               CCP-5F.F.F 12.0%                                                               Example 7                                                                      PCH-5F     8.0%    S → N [°C.]                                                                    --                                            PCH-7F     4.0%    Clearing point [°C.]                                                                  +81                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0907                                       CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5672                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.46                                          BCH-3F.F.F 14.0%   V.sub.(50,0,20)                                                                              --                                            BCH-5F.F.F 10.0%   V.sub.(90,0,20)                                                                              --                                            CCP-3F.F.F 10.0%                                                               CCP-5F.F.F 8.0%                                                                ECCP-3F.F  4.0%                                                                Example 8                                                                      PCH-5F     8.0%    S → N [°C.]                                                                    --                                            CCP-20CF.sub.3                                                                            10.0%   Clearing point [°C.]                                                                  +86                                           CCP-30CF.sub.3                                                                            12.0%   Viscosity 20° C.                                                                      --                                            CCP-40CF.sub.3                                                                            8.0%    Δn (589 nm, 20° C.)                                                             +0.0930                                       CCP-50CF.sub.3                                                                            12.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5697                                        BCH-3F.F.F 14.0%   V.sub.(10,0,20)                                                                              1.45                                          BCH-5F.F.F 11.0%   V.sub.(50,0,20)                                                                              1.89                                          CCP-3F.F.F 12.0%   V.sub.(90,0,20)                                                                              2.46                                          CCP-5F.F.F 7.0%                                                                ECCP-3F.F  6.0%                                                                Example 9                                                                      PCH-5F     11.0%   S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +84                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0908                                       CCP-40CF.sub.3                                                                            10.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5655                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.65                                          BCH-3F.F.F 10.0%   V.sub.(50,0,20)                                                                              2.13                                          BCH-5FCF.sub.3                                                                            10.0%   V.sub.(90,0,20)                                                                              2.76                                          ECCP-3F.F  10.0%                                                               ECCP-5F.F  8.0%                                                                Example 10                                                                     PCH-5F     11.0%   S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +82                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0887                                        CCP-40CF.sub.3                                                                            10.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5657                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.62                                          BCH-3F.F.F 10.0%   V.sub.(50,0,20)                                                                              2.10                                          BCH-5F.F.F 10.0%   V.sub.(90,0,20)                                                                              2.73                                          ECCP-3F.F  10.0%                                                               ECCP-5F.F  8.0%                                                                Example 11                                                                     PCH-5F     12.0%   S → N [°C.]                                                                    --                                            PCH-7F     10.0%   Clearing point [°C.]                                                                  +77                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0837                                        CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5601                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.71                                          ECCP-3F.F  10.0%   V.sub.(50,0,20)                                                                              2.17                                          ECCP-5F.F  10.0%   V.sub.(90,0,20)                                                                              2.76                                          BCH-5F.F.F 16.0%                                                               Example 12                                                                     PCH-5F     12.0%   S → N [°C.]                                                                    --                                            PCH-7F     10.0%   Clearing point [°C.]                                                                  +77                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0853                                        CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5613                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.64                                          ECCP-3F.F  10.0%   V.sub.(50,0,20)                                                                              2.12                                          ECCP-5F.F  10.0%   V.sub.(90,0,20)                                                                              2.75                                          BCH-3F.F.F 8.0%                                                                BCH-5F.F.F 8.0%                                                                Example 13                                                                     PCH-5F     12.0%   S → N [ °C.]                                                                   --                                            PCH-7F     10.0%   Clearing point [°C.]                                                                  +77                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0837                                        CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5601                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.71                                          ECCP-3F.F  10.0%   V.sub.(50,0,20)                                                                              2.17                                          ECCP-5F.F  10.0%   V.sub.(90,0,20)                                                                              2.76                                          BCH-5F.F.F 16.0%                                                               Example 14                                                                     PCH-5F     14.0%   S → N [°C.]                                                                    --                                            PCH-7F     6.0%    Clearing point [°C.]                                                                  +78                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0871                                        CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5644                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.64                                          ECCP-3F.F  10.0%   V.sub.(50,0,20)                                                                              2.10                                          ECCP-5F.F  8.0%    V.sub.(90,0,20)                                                                              2.68                                          BCH-3F.F.F 8.0%                                                                BCH-5F.F.F 12.0%                                                               Example 15                                                                     PCH-5F     14.0%   S → N [°C.]                                                                    --                                            PCH-7F     8.0%    Clearing point [°C.]                                                                  +74                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                              +0.0867                                      CCP-40CF.sub.3                                                                            7.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5643                                        CCP-50CF.sub.3                                                                            11.0%   V.sub.(10,0,20)                                                                              1.61                                          ECCP-3F.F  10.0%   V.sub.(50,0,20)                                                                              2.04                                          ECCP-5F.F  8.0%    V.sub.(90,0,20)                                                                              2.62                                          BCH-3F.F.F 12.0%                                                               BCH-5F.F.F 8.0%                                                                Example 16                                                                     PCH-5F     12.0%   S → N [°C.]                                                                    --                                            PCH-7F     9.0%    Clearing point [°C.]                                                                  +75                                           CCP-20CF.sub.3                                                                            11.0%   Viscosity 20° C.                                                                      15                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0874                                       CCP-40CF.sub.3                                                                            7.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5650                                        CCP-50CF.sub.3                                                                            11.0%   V.sub.(10,0,20)                                                                              1.55                                          ECCP-3F.F  10.0%   V.sub.(50,0,20)                                                                              2.00                                          ECCP-5F.F  7.0%    V.sub.(90,0,20)                                                                              2.60                                          BCH-3F.F.F 12.0%                                                               BCH-5F.F.F 9.0%                                                                Example 17                                                                     PCH-5F     11.0%   S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +84                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0908                                       CCP-40CF.sub.3                                                                            10.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5655                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.65                                          BCH-3F.F.F 10.0%   V.sub.(50,0,20)                                                                              2.13                                          BCH-5FCF.sub.3                                                                            10.0%   V.sub.(90,0,20)                                                                              2.76                                          ECCP-3F.F  10.0%                                                               ECCP-5F.F  8.0%                                                                 Example 18                                                                    PCH-5F     11.0%   S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +88                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0925                                       CCP-40CF.sub.3                                                                            10.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5641                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.74                                          BCH-3F.F.F 10.0%   V.sub.(50,0,20)                                                                              2.21                                          BCH-5FCF.sub.3                                                                            10.0%   V.sub.(90,0,20)                                                                              2.84                                          ECCP-30CF.sub.3                                                                           10.0%                                                               ECCP-50CF.sub.3                                                                           8.0%                                                                Example 19                                                                     CCH-32CF.sub.3                                                                            14.0%   S → N [°C.]                                                                    --                                            CCH-52CF.sub.3                                                                            14.0%   Clearing point [°C.]                                                                  +83                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0905                                       CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5575                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.68                                          BCH-3F.F.F 15.0%   V.sub.(50,0,20)                                                                              2.14                                          BCH-5F.F.F 15.0%   V.sub.(90,0,20)                                                                              2.75                                          Example 20                                                                     PCH-5F     11.0%   S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +86                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0903                                       CCP-40CF.sub.3                                                                            10.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5636                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.70                                          BCH-3F.F.F 10.0%   V.sub.(50,0,20)                                                                              2.18                                          BCH-5F.F.F 10.0%   V.sub.(90,0,20)                                                                              2.82                                          ECCP-30CF.sub.3                                                                           10.0%                                                               ECCP-50CF.sub.3                                                                           8.0%                                                                Example 21                                                                     PCH-5F     11.0%   S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +82                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0887                                        CCP-40CF.sub.3                                                                            10.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5657                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.62                                          BCH-3F.F.F 10.0%   V.sub.(50,0,20)                                                                              2.10                                          BCH-5F.F.F 10.0%   V.sub.(90,0,20)                                                                              2.73                                          ECCP-3F.F  10.0%                                                               ECCP-5F.F  8.0%                                                                Example 22                                                                     PCH-5F     10.0%   S → N [°C.]                                                                    --                                            PCH-7F     6.0%    Clearing point [°C.]                                                                  +83                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0918                                       CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5697                                        CCP-50CF.sub.3                                                                            12.0%   V.sub. (10,0,20)                                                                             1.58                                          BCH-3F.F.F 15.0%   V.sub.(50,0,20)                                                                              2.02                                          BCH-5F.F.F 9.0%    V.sub.(90,0,20)                                                                              2.61                                          ECCP-3F.F  10.0%                                                               ECCP-5F.F  8.0%                                                                Example 23                                                                     PCH-5F     9.0%    S → N [°C.]                                                                    --                                            PCH-7F     4.0%    Clearing point [°C.]                                                                  +87                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0938                                        CCP-40CF.sub.3                                                                            9.0%    n.sub.ε  (589 nm, 20° C.)                                                     --                                            CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.58                                          BCH-3F.F.F 15.0%   V.sub.(50,0,20)                                                                              --                                            BCH-5F.F.F 10.0%   V.sub.(90,0,20)                                                                              --                                            ECCP-3F.F  11.0%                                                               ECCP-5F.F  8.0%                                                                Example 24                                                                     PCH-5F     10.0%   S → N [°C.]                                                                    --                                            PCH-7F     5.0%    Clearing point [°C.]                                                                  +84.7                                         CCP-20CF.sub.3                                                                            11.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0910                                        CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     --                                            CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.60                                          BCH-3F.F.F 14.0%   V.sub.(50,0,20)                                                                              --                                            BCH-5F.F.F 9.0%    V.sub.(90,0,20)                                                                              --                                            ECCP-3F.F  11.0%                                                               ECCP-5F.F  8.0%                                                                Example 25                                                                     PCH-5F     8.0%    S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +85.3                                         CCP-20CF.sub.3                                                                            12.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            14.0%   Δn (589 nm, 20° C.)                                                             0.0914                                        CCP-40CF.sub.3                                                                            9.0%    n.sub.ε  (589 nm, 20° C.)                                                     --                                            CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              --                                            BCH-3F.F.F 14.0%   V.sub.(50,0,20)                                                                              --                                            BCH-5F.F.F 9.0%    V.sub.(90,0,20)                                                                              --                                            ECCP-3F.F  8.0%                                                                ECCP-5F.F  7.0%                                                                Example 26                                                                     PCH-5F     8.0%    S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +84.7                                         CCP-20CF.sub.3                                                                            12.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0910                                       CCP-40CF.sub.3                                                                            10.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5679                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.61                                          BCH-3F.F.F 12.0%   V.sub.(50,0,20)                                                                              2.07                                          BCH-5F.F.F 11.0%   V.sub.(90,0,20)                                                                              2.68                                          ECCP-3F.F  8.0%                                                                ECCP-5F.F  8.0%                                                                Example 27                                                                     PCH-5F     10.0%   S → N [°C.]                                                                    --                                            PCH-7F     10.0%   Clearing point [°C.]                                                                  +84                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0880                                       CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5606                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.76                                          CCH-52CF.sub.3                                                                            15.0%   V.sub.(50,0,20)                                                                              2.24                                          BCH-3F.F.F 15.0%   V.sub.(90,0,20)                                                                              2.89                                          CBC-33F    4.0%                                                                CBC-53F    4.0%                                                                Example 28                                                                                        S → N [°C.]                                                                    --                                                               Clearing point [°C.]                                                                  +101                                          PCH-7F     4.0%    Viscosity 20° C.                                                                      --                                            CCP-20CF.sub.3                                                                            10.0%   Δn (589 nm, 20° C.)                                                             +0.0934                                       CCP-30CF.sub.3                                                                            12.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5608                                        CCP-40CF.sub.3                                                                            8.0%    V.sub.(10,0,20)                                                                              1.90                                          CCP-50CF.sub.3                                                                            12.0%   V.sub.(50,0,20)                                                                              2.42                                                             V.sub.(90,0,20)                                                                              3.07                                          CCH-32CF.sub.3                                                                            10.0%                                                               CCH-52CF.sub.3                                                                            10.0%                                                               ECCP-3F.F  10.0%                                                               BCH-3F.F.F 12.0%                                                               BCH-5.FCF.sub.3                                                                           12.0%                                                               Example 29                                                                     PCH-7F     4.0%    S → N [°C.]                                                                    --                                            CCP-20CF.sub.3                                                                            10.0%   Clearing point [°C.]                                                                  +82                                           CCP-30CF.sub.3                                                                            12.0%   Viscosity 20° C.                                                                      --                                            CCP-40CF.sub.3                                                                            8.0%    Δn (589 nm, 20° C.)                                                             +0.0883                                       CCP-50CF.sub.3                                                                            12.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5519                                        CCH-32CF.sub.3                                                                            15.0%   V.sub.(10,0,20)                                                                              1.82                                          CCH-52CF.sub.3                                                                            15.0%   V.sub.(50,0,20)                                                                              2.29                                          BCH-3F.F.F.                                                                               12.0%   V.sub.(90,0,20)                                                                              2.89                                          BCH-5.FCF.sub.3                                                                           12.0%                                                               Example 30                                                                     CCH-32CF.sub.3                                                                            14.0%   S → N [°C.]                                                                    --                                            CCH-52CF.sub.3                                                                            14.0%   Clearing point [°C.]                                                                  +83                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0905                                       CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5575                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.68                                          BCH-3F.F.F 15.0%   V.sub.(50,0,20)                                                                              2.14                                          BCH-5F.F.F 15.0%   V.sub.(90,0,20)                                                                              2.75                                          Example 31                                                                     CCP-20CF.sub.3                                                                            10.0%   S → N [°C.]                                                                    --                                            CCP-30CF.sub.3                                                                            12.0%   Clearing point [°C.]                                                                  +99                                           CCP-40CF.sub.3                                                                            8.0%    Viscosity 20° C.                                                                      --                                            CCP-50CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0840                                        ECCP-3F.F  10.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5520                                        ECCP-5F.F  10.0%   V.sub.(10,0,20)                                                                              1.99                                          BCH-5F.F.F 16.0%   V.sub.(50,0,20)                                                                              2.51                                          CCH-32CF.sub.3                                                                            12.0%   V.sub.(90,0,20)                                                                              3.22                                          CCH-52CF.sub.3                                                                            10.0%                                                               Example 32                                                                     PCH-5F     8.0%    S → N [°C.]                                                                    --                                            CCP-20CF.sub. 3                                                                           10.0%   Clearing point [°C.]                                                                  +74.5                                         CCP-30CF.sub.3                                                                            12.0%   Viscosity 20° C.                                                                      --                                            CCP-40CF.sub.3                                                                            8.0%    Δn (589 nm, 20° C.)                                                             0.0893                                        CCP-50CF.sub.3                                                                            12.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5598                                        BCH-3F.F.F 15.0%   V.sub.(10,0,20)                                                                              1.55                                          BCH-5F.F.F 15.0%   V.sub.(50,0,20)                                                                              1.99                                          CCH-32CF.sub.3                                                                            10.0%   V.sub.(90,0,20)                                                                              2.57                                          CCH-52CF.sub.3                                                                            10.0%                                                               Example 33                                                                     PCH-5F     10.0%   S → N [°C.]                                                                    --                                            PCH-7F     10.0%   Clearing point [°C.]                                                                  +89                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.1019                                       CCP-40CF.sub.3                                                                            8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1,5801                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.66                                          BCH-3F.F.F 15.0%   V.sub.(50,0,20)                                                                              2.11                                          BCH-5.FCF.sub.3                                                                           15.0%   V.sub.(90,0,20)                                                                              2.74                                          CBC-33F    4.0%                                                                CBC-53F    4.0%                                                                Example 34                                                                     PCH-5F     10.0%   S → N [°C.]                                                                    --                                            PCH-7F     10.0%   Clearing point [°C.]                                                                  +84                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0880                                       CCP-40CF.sub. 3                                                                           8.0%    n.sub.ε  (589 nm, 20° C.)                                                     1.5606                                        CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.76                                          CCH-52CF.sub.3                                                                            15.0%   V.sub.(50,0,20)                                                                              2.24                                          BCH-3F.F.F 15.0%   V.sub.(90,0,20)                                                                              2.89                                          CBC-33F    4.0%                                                                CBC-53F    4.0%                                                                Example 35                                                                     PCH-5F     10.0%   S → N [°C.]                                                                    --                                            CCP-20CF.sub.3                                                                            10.0%   Clearing point [°C.]                                                                  +86                                           CCP-30CF.sub.3                                                                            12.0%   Viscosity 20° C.                                                                      --                                            CCP-40CF.sub.3                                                                            8.0%    Δn (589 nm, 20° C.)                                                             +0.0976                                       CCP-50CF.sub.3                                                                            12.0%   n.sub.ε  (589 nm, 20° C.)                                                     1.5695                                        CCH-32CF.sub.3                                                                            7.0%    V.sub.(10,0,20)                                                                              1.70                                          CCH-52CF.sub.3                                                                            7.0%    V.sub.(50,0,20)                                                                              2.17                                          BCH-3F.F.F 15.0%   V.sub.(90,0,20)                                                                              2.76                                          BCH-5.FCF.sub.3                                                                           15.0%                                                               CBC-33F    4.0%                                                                Example 36                                                                     PCH-5F     9.0%                                                                PCH-7F     5.0%                                                                CCP-20CF.sub.3                                                                            10.0%                                                               CCP-30CF.sub.3                                                                            12.0%                                                               CCP-40CF.sub.3                                                                            9.0%                                                                CCP-50CF.sub.3                                                                            12.0%                                                               BCH-3F.F.F 15.0%                                                               BCH-5F.F.F 10.0%                                                               ECCP-3F.F  10.0%                                                               ECCP-5F.F  8.0%                                                                Example 37                                                                     PCH-5F     9.0%                                                                PCH-7F     6.0%                                                                CCP-20CF.sub.3                                                                            12.0%                                                               CCP-30CF.sub.3                                                                            12.0%                                                               CCP-40CF.sub.3                                                                            10.0%                                                               CCP-50CF.sub.3                                                                            12.0%                                                               BCH-3F.F.F 12.0%                                                               BCH-5F.F.F 10.0%                                                               ECCP-3F.F  10.0%                                                               ECCP-5F.F  7.0%                                                                Example 38                                                                     PCH-5F     12.0%   S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +85                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0895                                       CCP-40CF.sub.3                                                                            10.0%                                                               CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.76                                          BCH-3F.F.F 26.0%   V.sub.(50,0,20)                                                                              2.10                                          CP-3F      6.0%    V.sub.(90,0,20)                                                                              2.60                                          CP-5F      5.0%                                                                Example 39                                                                     PCH-6F     13.0%   S → N [°C.]                                                                    --                                            PCH-7F     7.0%    Clearing point [°C.]                                                                  +86                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            11.0%   Δn (589 nm, 20° C.)                                                             +0.0905                                       CCP-40CF.sub.3                                                                            10.0%                                                               CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.72                                          BCH-3F.F.F 24.0%   V.sub.(50,0,20)                                                                              2.06                                          CP-3F      6.0%    V.sub.(90,0,20)                                                                              2.51                                          CP-5F      7.0%                                                                Example 40                                                                     PCH-5F     8.0%    S → N [°C.]                                                                    --                                            PCH-7F     5.0%    Clearing point [°C.]                                                                  +89                                           CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             +0.0927                                       CCP-40CF.sub.3                                                                            8.0%                                                                CCP-50CF.sub.3                                                                            10.0%   V.sub.(10,0,20)                                                                              1.61                                          BCH-3F.F   10.0%   V.sub.(50,0,20)                                                                              2.07                                          BCH-5F.F   10.0%   V.sub.(90,0,20)                                                                              2.69                                          CCP-5F.F.F 9.0%                                                                ECCP-3F.F  6.0%                                                                CCP-3CF.sub.3.F.F                                                                         12.0%                                                               Example 41                                                                     PCH-5F     10.0%   S →  N [°C.]                                                                   --                                            PCH-6F     7.0%    Clearing point [°C.]                                                                  63                                            PCH-7F     15.0%   Viscosity 20° C.                                                                      --                                            CCP-20CF.sub.3                                                                            10.0%   Δn (589 nm, 20° C.)                                                             0.0816                                        CCP-30CF.sub.3                                                                            12.0%                                                               CCP-40CF.sub.3                                                                            8.0%    V.sub.(10,0,20)                                                                              1.55                                          CCP-50CF.sub.3                                                                            12.0%   V.sub.(50,0,20)                                                                              1.99                                          CCP-3CF.sub.3.F.F                                                                         10.0%   V.sub.(90,0,20)                                                                              2.62                                          BCH-5F.F   16.0%                                                               Example 42                                                                     PCH-5F     12.0%   S → N [°C.]                                                                    --                                                               Clearing point [°C.]                                                                  79.7                                          PCH-7F     8.0%    Viscosity 20° C.                                                                      --                                            CCP-20CF.sub.3                                                                            10.0%   Δn (589 nm, 20° C.)                                                             0.0779                                        CCP-30CF.sub.3                                                                            12.0%                                                               CCP-40CF.sub.3                                                                            8.0%    V.sub.(10,0,20)                                                                              1.64                                          CCP-50CF.sub.3                                                                            12.0%   V.sub.(50,0,20)                                                                              --                                            ECCP-3F.F  12.0%   V.sub.(90,0,20)                                                                              --                                            CCP-5F.F.F 12.0%                                                               CCP-3CF.sub.3.F.F                                                                         14.0%                                                               Example 43                                                                     PCH-5F     10.0%   S → N [°C.]                                                                    --                                            PCH-7F     8.0%    Clearing point [°C.]                                                                  84                                            CCP-20CF.sub.3                                                                            10.0%   Viscosity 20° C.                                                                      --                                            CCP-30CF.sub.3                                                                            12.0%   Δn (589 nm, 20° C.)                                                             0.0791                                        CCP-40CF.sub.3                                                                            10.0%                                                               CCP-50CF.sub.3                                                                            12.0%   V.sub.(10,0,20)                                                                              1.78                                          ECCP-3F.F  12.0%   V.sub.(50,0,20)                                                                              --                                            CCP-3CF.sub.3.F.F                                                                         26.0%   V.sub.(90,0,20)                                             ______________________________________                                    

The following are further examples of media according to the invention:

      example 44 45 46 47 48 49 50        Clearing point [°C.]  +77  +76  +81  +86  +89  +81.2  +80      Viscosity [mm.sup.2 s.sup.-1 ]  --  --  --  --  --  --  -- -20°      C. Δn (589 nm, 20° C.)  +0.0847  0.0835  +0.0907  +0.0930      +0.0857  +0.0865  +0.0881 n.sub.e (589 nm, 20° C.)  1.5605      1.5595  1.5672  1.5697  1.5587  1.5630  1.5635 Δε (1 kHz,      20° C.)  --  --  --  --  --  --  -- .sup.ε ∥ (1      kHa, 20° C.)  --  --  --  --  --  --   -- d · Δn      [μm] = 0.4  --  --  --  --  --  --  -- V.sub.(10,0,20) [V]  1.59      1.49  1.46  1.45  1.74  1.47  1.42 V.sub.(60,0,20) [V]  --  1.93  --      1.89  2.23  1.90  1.84 V.sub.(90,0,20) [V]  --  2.52  --  2.46  2.90      2.48 PCH-5F 8.0 Composition [%] PCH-5F 12.0 PCH-5F 12.0 PCH-5F 8.0      PCH-5F 8.0 PCH-5F 9.0 PCH-5F 8.0 PCH-7F 5.0    PCH-7F 7.0       PCH-7F      5.0 CCP-20CF3 11.0  PCH-7F 8.0 CCP-20CF3 10.0 PCH-7F 4.0 CCP-20CF3 10.0      PCH-7F 6.0 CCP-20CF3 10.0 CCP-30CF3 12.0  CCP-20CF3 10.0 CCP-30CF3 12.0      CCP-20CF3 10.0 CCP-30CF3 12.0 CCP-20CF3 12.0 CCP-30CF3 12.0 CCP-40CF3      9.0  CCP-30CF3 12.0 CCP-40CF3 8.0 CCP-30CF3 12.0 CCP-40CF3 8.0 CCP-30CF3      12.0 CCP-40CF3 8.0 CCP-50CF3 11.0  CCP-40CF3 8.0 CCF-50CF3 12.0 CCP-40CF3       8.0 CCP-50CF3 12.0 CCP-40CF3 10.0 CCP-50CF3 10.0 BCH-3F.F.F 10.0      CCP-50CF3 12.0 BCH-3F.F.F 8.0 CCP-50CF3 12.0 BCH-3F.F.F 14.0 CCP-50CF3      12.0 BCH-3F.F.F 10.0 BCH-5F.F.F 11.0  BCH-3F.F.F 14.0 BCH-5F.F 6.0      BCH-3F.F.F 14.0 BCH-5F.F.F 11.0   BCH-5F.F.F 10.0 CCP-3F.F.F 12.0      BCCP-3F.F 12.0 CCP-3F.F.F 13.0 BCH-5F.F.F 10.0 CCP-3F.F.F 12.0 BCH-5F.F.F       10.0 CCP-3F.F.F 12.0 CCP-5F.F.F 11.0  CCP-5F.F.F 12.0 CCP-5F.F.F 12.0      CCP-3F.F.F 10.0 CCP-5F.F.F 7.0 ECCP-3F.F 10.0 CCP-5F.F.F 9.0      CCP-5F.F.F 8.0 ECCP-3F.F. 6.0 ECCP-5F.F 7.0 ECCP-3F.F 6.0      ECCP-3F.F      4.0   CCP-3CF3.F.F 12.0        example 51 52 53 54 55 56        Clearing point [°C.]  +87.5  84.3  +86  +87  +87  +82 Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  +0.0930  --  200  188  188  --      Δn (589 nm, 20° C.)  --  +0.0928  +0.0920  +0.0919  +0.0919       +0.0942 n.sub.e (589 nm, 20° C.)  1.5695  1.5693  1.5683  1.5679       1.5679  1.5679 Δε (1 kHz, 20° C.)  --  --  --  7.9       7.9  -- .sup.ε ∥(1 kHz, 20° C.)  --  --  --      11.1  11.1  -- d · Δn [μm] = 0.4  --  --  --  --  --      -- V.sub.(10,0,20) [V]  1.48  1.43  1.46  1.56  1.56  1.46 V.sub.(60,0,20      ) [V]  1.92  1.84  1.89  1.93  1.93  1.88 V.sub.(90,0,20) [V]  2.50      2.38  2.47  2.41  2.41  2.45 Composition [%] PCH-5F 7.0 PCH-5F 10.0      PCH-5F 7.0 PCH-5F 5.0 PCH-5F 5.0 PCH-5F 8.0  PCH-7F 4.0 CCP-20CF3 10.0      PCH-7F 4.0 PCH-7F 6.0 PCH-7F 6.0  CCP-20CF3 11.0 CCP-30CF3 14.0 CCP-20CF3       11.0 CCP-20CF3 11.0 CCP-20CF3 11.0 PCH-7F 4.0  CCP-40CF3 9.0 CCP-40CF3      10.0 CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-20CF3 10.0      CCP-50CF3 11.0 CCP-50CF3 10.0 CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3      10.0 CCP-30CF3 12.0  BCH-3F.F.F 11.0 BCH-3F.F.F 14.0 CCP-50CF3 11.0      CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-40CF3 8.0  BCH-5F.F.F 11.0 BCH-5F.F.F      10.0 BCH-3F.F.F 11.0 BCH-3F.F.F 12.0 BCH-3F.F.F 12.0 CCP-50CF3 12.0      CCP-3F.F.F 12.0 CCP-3F.F.F 14.0 BCH-5F.F.F 11.0 BCH-5F.F.F 11.0 BCH-5F.F.      F 11.0 BCH-3F.F.F 14.0  CCP-5F.F.F 10.0 CCP-5F.F.F 8.0 CCP-3F.F.F 12.0      CCP-3F.F.F 12.0 CCP-3F.F.F 12.0 BCH-5F.F.F 10.0  CBC-33F 2.0   CCP-5F.F.F       10.0 CCP-5F.F.F 9.0 CCP-5F.F.F. 9.0 CCP-3CF3.F.F 10.0      CBC-33F 1.0         CCP-5CF3.F.F 8.0            ECCP-3F.F 4.0        example 57 58 59 60 61 62        Clearing Point [°C.]  +88  +85  59.7  +85  +90  +96.5 Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  --  smect.  --  --  --  -- Δn      (589 nm, 20° C.)  +0.0978  +0.1348  0.1006  +0.1363  +.0990      +0.1020 n.sub.e (589 nm, 20° C.)  1.5714  1.6176  1.5905  1.6173      1.5775  1.5804 Δε (1 kHz, 20° C.)  --  --  +9.36      --  --  -- .sup.ε ∥ (1 kHz, 20° C.)  --  --      13.07  --  --  -- d · Δn [μm] = 0.4  --  --  --  --      --  -- V.sub.(10,0,20) [V]  1.46  --  --  --  1.51  1.55 V.sub.(60,0,20)      [V]  1.89  --  --  --  1.96  2.01 V.sub.(90,0,20) [V]  2.46  --  --  --      2.56  2.60 Composition [%] PCH-5F 8.0 PCH-5F 10.0 CCP-3F.F.F. 25.0      PCH-5F 10.0 PCH-5F 8.0 PCH-5F 8.0    PTP-40F 10.0 CCP-5F.F.F 15.0      PTP-40F 10.0 PCH-7F 4.0 CCP-20CF3 10.0  CCP-20CF3 10.0 PTP-50F 10.0      BCH-3F.F.F 20.0 PTP-50F 10.0 CCP-20CF3 10.0 CCP-30CF3 12.0  CCP-30CF3      12.0 CCP-20CF3 7.0 BCH-5F.F.F 40.0 CCP-20CF3 7.0 CCP-30CF3 12.0 CCP-40CF3       8.0  CCP-40CF3 8.0 CCP-30CF3 7.0   CCP-30CF3 7.0 CCP-40CF3 8.0 CCP-50CF3       12.0  CCP-50CF3 12.0 CCP-40CF3 7.0   CCP-40CF3 7.0 CCP-50CF3 12.0      BCH-3F.F.F 14.0  BCH-3F.F.F 14.0 CCP-50CF3 7.0   CCP-50CF3 7.0 BCH-3F.F.F       14.0 BCH-5F.F.F 1.0  BCH-5F.F.F 11.0 ECCP-30CF3 5.0   BCCP-30CF3 5.0      BCH-5F.F.F 10.0 CCP-3CL.F.F 12.0  CCP-3CF3.F.F 12.0 ECCP-3F.F 7.0      BCCP-3F.F 7.0 CCP-3CL.F.F 10.0 CCP-5CL.F.F 7.0  CCP-5CF3.F.F 7.0      BCH-3F.F.F 5.0   BCH-3F.F.F 5.0 CCP-5CL.F.F 8.0 ECCP-3F.F 6.0  ECCP-3F.F      6.0 BCH-5F.F.F 5.0   BCH-5F.F.F 5.0 ECCP-3F.F 4.0    CCP-3F.F.F 5.0      CCP-5CF3.F.F 10.0    CCP-5F.F.F 5.0   CPTP-30CF3 5.0    CPTP-30CF3 5.0      CPTP-50CF3 5.0    CPTP-50CF3 5.0        example 63 64 65 66 67 68        Clearing Point [°C.]  +94  +100  +83  --  +85  +64 Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --  --  --  -- Δn      (589 nm, 20° C.)  +0.1010  +0.1045  +0.0903  +0.0934  +0.0864      +0.0897 n.sub.e (589 nm, 20° C.)  1.5795  1.5832  1.5650  1.5667      1.5594  1.5716 Δε (1 kHz, 20° C.)  --  --  --  --      --  -- p.sup.ε ∥ (1 kHz, 20° C.)  --  --  --  --       --  -- d · Δn [μm] = 0.4  --  --  --  --  --  --      V.sub.(10,0,20) [V]  1.57  1.54  1.37  1.51  1.50  1.22 V.sub.(60,0,20)      [V]  2.02  1.98  1.78  1.96  1.96  1.60 V.sub.(90,0,20) [V]  2.60  2.58      2.32  2.55  2.58  2.08 Composition [%] PCH-5F 8.0 PCH-5F 8.0 PCH-5F 5.0      PCH-5F 5.0 PCH-5F 6.0 PCH-5F 12.0  PCH-7P 4.0 CCP-20CF3 10.0 PCH-7F 6.0      PCH-7F 6.0 PCH-7F 7.0 PCH-7F 6.0  CCP-20CF3 10.0 CCP-30CF3 12.0 CCP-20CF3       11.0 CCP-20CF3 11.0 CCP-20CF3 12.0 CCP-3F.F.F 10.0  CCP-30CF3 12.0      CCP-40CF3 8.0 CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3 13.0 CCP-5F.F.F      9.0  CCP-40CF3 8.0 CCF-50CF3 12.0 CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3       12.0 BCH-3F.F.F 10.0  CCP-50CF3 12.0 BCH-5CL.F.F 25.0 CCP-50CF3 12.0      CCP-50CF3 12.0 CCP-50CF3 13.0 BCH-5F.F.F 9.0  BCH-5CL.F.F 24.0 CCP-3F.F.F       12.0 CUP-3F.F 12.0 BCH-3F.F.F 12.0 CUP-3F.F 12.0 CCP-5CF3.F.F 15.0      CCP-3F.F.F 10.0 CCP-5F.F.F 7.0 BCH-5F.F.F 11.0 BCH-5.F0CF3 11.0 BCH-5F.F.      F 4.0 CCP-3CL.F.F 15.0  CCP-5F.F.F 8.0 ECCP-3F.F 6.0 CCP-3F.F.F 12.0      CCP-3F.F.F 12.0 CCP-3F.F.F 12.0 CCP-5CL.F.F 14.0  ECCP-3F.F 4.0      CCP-5F.F.F 9.0 CCP-5F.F.F 9.0 CCP-5F.F.F 9.0        example 69 70 71 72 73 74        Clearing Point [°C.]  +88  +88  >-30  +90  +68  +94       +87      Viscosity [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --  --  --  --      Δn (589 nm, 20° C.)  +0.0963  +0.0958  +0.0945  +0.0993      +0.0818  +0.0885 n.sub.e (589 nm, 20° C.)  1.5776  1.5727  1.5710       1.5767  1.5573  1.5635 Δε (1 kHz, 20° C.)  --  --      --  --  --  +7.2 .sup.ε ∥ (1 kHz, 20° C.)  --      --  --  --  --  10.4 d · Δn [μm] = 0.4  --  --  --  --       --  -- V.sub.(10,0,20) [V]  1.31  1.49  1.48  1.51  1.42  1.62 V.sub.(60      ,0,20) [V]  1.73  1.95  1.93  1.96  1.80  2.11 V.sub.(90,0,20) [V]      2.28  2.54  2.51  2.55  2.27  2.74 Composition [%] PCH-5F 5.0 PCH-5F 5.0      PCH-5F 5.0 PCH-5F 5.0 PCH-5F 10.0 PCH-5F 5.0  PCH-7F 4.0 PCH-7F 6.0      PCH-7F 6.0 PCH-7F 6.0 PCH-6F 8.0 PCH-6F 8.0  CCP-3F.F.F 10.0 CCP-20CF3      11.0 CCP-20CF3 11.0 CCP-20CF3 11.0 PCH-7F 7.0 CCP-20CF3 11.0  CCP-5F.F.F      10.0 CCP-30CF3 12.0 CP-30CF3 12.0 CCP-30CF3 12.0 CCP-20CF3 11.0 CP-30CF3      12.0  BCH-3F.F.F 10.0 CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3 10.0      CCP-30CF3 12.0 CCP-40CF3 10.0  BCH-5F.F.F 8.0 CCP-50CF3 12.0 CCP-50CF3      12.0 CCP-50CF3 12.0 CCP-40CF3 10.0 CCP-50CF3 12.0  CCP-5CF3.F.F 15.0      BCH-3F.F.F 12.0 BCH-3F.F.F 12.0 BCH-3F.F 7.0 CCP-50CF3 12.0 ECCP-3F.F      7.0  CCP-3CL.F.F 14.0 BCH-5F.F.F 11.0 BCH-5F.F.F 11.0 BCH-5F.F 7.0      BCH-3F.F.F 8.0 ECCP-5F.F 7.0  CCP-5CL.F.F 14.0 CCP-3CL.F.F 12.0 CCP-3F.F.      F 12.0 BCH-3F.F.F 8.0 BCH-5F.F.F 8.0 BCH-3F.F.F 8.0  CP-3F 5.0 CCP-5F.F.F       9.0 CCP-5CL.F.F 9.0 BCH-5F.F.F 8.0 CCP-3F.F.F 8.0 BCH-5F.F.F 8.0      CP-5F 5.0   CCP-3F.F.F 8.0 CCP-5F.F.F 6.0 CCP-3F.F.F 8.0        CCP-5F.F.      F 6.0   CCP-5F.F.F 6.0        example 75 76 77 78 79 80        Clearing Point [°C.]   +92  +96  +78  +84  +78  +86  Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --  --  --  -- Δn      (589 nm, 20° C.)  +0.0915  +0.0909  +0.0861  +0.0896  +0.0886      +0.0920 n.sub.e (589 nm, 20° C.)  1.5680  1.5670  1.5612  1.5658      1.5645  1.5695 Δε (1 kHz, 20° C.)  --  --  --  --      --  -- .sup.ε ∥ (1 kHz, 20° C.)  --  --  --  --      --  -- d · Δn [μm] = 0.4  --  --    --  --  --      V.sub.(10,0,20) [V]  1.59  1.61  1.55  1.39  1.33  1.36 V.sub.(60,0,20)      [V]  2.05  2.07  1.99  1.81  1.72  1.79 V.sub.(90,0,20) [V]  2.66  2.67      2.58  2.35  2.25  2.36 Composition [%] PCH-5F 5.0 CH-5F 6.0 PCH-5F 5.0      PCH-5F 5.0 PCH-5F 5.0 PCH-5F 4.0  PCH-7F 6.0 PCH-7F 6.0 PCH-7F 6.0      PCH-7F 6.0 PCH-7F 6.0 PCH-7F 5.0  CCP-20CF3 1.0 CCP-20CF3 11.0 CCP-20CF3      11.0 CCP-20CF3 11.0 CCP-20CF3 8.0 CCP-20CF3 8.0  CCP-30CF3 12.0 CCP-30CF3       12.0 CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3 10.0 CCP-30CF3 10.0      CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3      8.0 CCP-40CF3 8.0  CCP-50CF3 12.0 CCF-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3       12.0 CCP-50CF3 10.0 CCP-50CF3 10.0  ECCP-3F.F 7.0 ECCP-33 8.0 PCH-53      8.0 BCH-3F.F.F 12.0 BCH-3F.F.F 12.0 BCH-3F.F.F 12.0  BCH-3F.F 7.0      BCH-3F.F.F 9.0 BCH-3F.F.F 9.0 BCH-5F.F.F 11.0 BCH-6F.F.F 11.0 BCH-5F.F.F      11.0  BCH-3F.F.F 8.0 BCH-5F.F.F 9.0 BCH-5F.F.F 9.0 CCP-2F.F.F 6.0      CCP-2F.F.F 7.0 CCP-2F.F.F 7.0  BCH-5F.F.F 8.0 CCP-3F.F.F 9.0 CCP-3F.F.F      9.0 CCP-3F.F.F 6.0 CCP-3F.F.F 8.0 CCP-3F.F.F 8.0  CCP-3F.F.F 8.0      CCP-5F.F.F 9.0 CCP-5F.F.F 9.0 CCP-4F.F.F 5.0 CCP-4F.F.F 7.0 CCP-4F.F.F      7.0  CCP-5F.F.F 6.0     CCP-5F.F.F 4.0 CCP-5F.F.F 8.0 CCP-5F.F.F 8.0             CBC-53F 2.0            CBC-53F 2.0        example 81 82 83 84 85 86        Clearing Point [°C.]  +86  +112  +72  +79  +84  +76 Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  --    540  --  --  -- Δn (589      nm, 20° C.)  +0.0919  +0.1589  +0.1271  0.0970  +0.0979  +0.0954      n.sub.e (589 nm, 20° C.)  1.5696  1.6584  1.6229  1.5750  1.5737      1.5718 Δε (1 kHz, 20° C.)  --  --  --  --  --  --      .sup.ε ∥ (1 kHz, 20° C.)  --  --  --  --   --      -- d · Δn [μm] =       0.5  --  --  --  --  --  -- V.sub.(10,0,20) [V]  1.35  2.00  1.41  1.33       1.40  1.29 V.sub.(60,0,20) [V]  1.78  2.27  1.79  1.75  1.83  1.69      V.sub.(90,0,20) [V]  2.33  2.78  2.35  2.33  2.41  2.25 Composition [%]      PCH-5F 4.0 CCP-3CL.F.F. 11.2 PCH-5F 10.0 PCH-5F 5.0 PCH-5F 5.0 PCH-5F      5.0  PCH-7F 5.0 CCP-5CL.F.F 21.4 PCH-7F 10.0 PCH-7F 6.0 PCH-7F 6.0      PCH-7F 6.0  CCP-20CF3 8.0 BCH-3CL.F.F 25.9 CCP-3CL.F.F 10.0 CCP-20CF3      11.0 CCP-20CF3 11.0 CCP-20CF3 11.0  CCP-30CF3 10.0 BCH-5CL.F.F 41.5      CCP-5CL.F.F 20.0 CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3 12.0  CCP-40CF3      8.0   CCP-3CL.F.F 20.0 CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3 10.0      CCP-50CF3 10.0   BCH-5CL.F.F 30.0 CCP-50CF3 12.0 BCH-3F.F.F 12.0      CCP-50CF3 12.0  CCP-2F.F.F 7.0     BCH-3F.F.F 12.0 BCH-5F.F.F 11.0      BCH-3F.F.F 12.0  CCP-3F.F.F 8.0     BCH-5F.F.F 11.0 CUP-30CF3 12.0      BCH-5F.F.F 11.0  CCP-4F.F.F 7.0     CUP-3F.F. 12.0 CCP-5F.F.F 9.0      CUP-3F.F.F 6.0  CCP-5F.F.F 8.0     CCP-5F.F.F 9.0   CUP-5F.F.F 6.0      BCH-3F.F.F 6.0     CCP-5F.F.F 9.0  BCH-4F.F.F 10.0        BCH-5F.F.F 7.0       CBC-53F 2.0        example 87 88 89 90 91 92        Clearing Point [°C.]  +92  +85  +95  +88  +88  +83  Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --  --  --  -- Δn      (589 nm, 20° C.)  0.096  0.096  0.100  0.097  0.096  0.0905      n.sub.e (589 nm, 20° C.)  1.569  1.568  1.577  1.572  1.570      1.5654 Δε (1 kHz, 20° C.)  --  --  --  --  --  --      .sup.ε ∥ (1 kHz, 20° C.)  --  --  --  --  --  --      d · Δn [μm] =       0.5  --  --  --  --  --  -- V.sub.(10,0,20) [V]  1.61  1.54  1.63  1.67       1.60  1.40 V.sub.(60,0,20) [V]  2.05  1.95  2.09  2.14  2.03  1.84      V.sub.(90,0,20) [V]  2.67  2.52  2.72  2.79  2.63  2.43 Composition [%]      PCH-5F 5.0 PCH-5F 5.0 PCH-5F 5.0 PCH-5F 5.0 PCH-5F 5.0 PCH-5F 5.0      PCH-7F 6.0 PCH-7F 6.0 PCH-7F 6.0 PCH-7F 6.0 PCH-7F 6.0 PCH-7F 6.0      CCP-20CF3 11.0 CCP-20CF3 11.0 CCP20CF3 11.0 CCP-20CF3 11.0 CCP-20CF3      11.0 CCP-20CF3 11.0  CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3 12.0      CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3 12.0  CCP-40CF3 10.0 CCP-40CF3      10.0 CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3 10.0      CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3      12.0 CCP-50CF3 12.0  BCH-3F.F.F 12.0 BCH-3F.F.F 12.0 BCH-3F.F.F 12.0      BCH-3F.F.F 12.0 BCH-3F.F.F 12.0 CUP-30CF3 12.0  BCH-5F.F.F 11.0 BCH-5F.F.      F 11.0 BCH-5F.F.F 11.0 BCH-5F.F.F 11.0 BCH-5F.F.F 11.0 BCH-5F.F.F 11.0               CCP-3F.F.F 12.0          CCP-5F.F.F 9.0 CCP-5F.F.F 9.0      CCP-3CF3.F.F 12.0 CCP-3CF3.F.F 12.0 CCP-3CI.F.F 12.0 CCP-30CF2.F 12.0      CCP-3CF3.F 12.0  CCP-5CF3.F.F 9.0 CCP-5CF3.F.F 9.0 CCP-5CI.F.F 9.0      CCP-40CF2.F 9.0        example 93  94  95  96  97        Clearing Point [°C.]  +88  +86    +92   +92   +88  Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  --   --   --   --   -- Δn      (589 nm, 20° C.)  +0.0913   +0.0946   +0.0941   +0.0984   0.093      n.sub.e (589 nm, 20° C.)  1.5633   1.5681   1.5674   1.5748      1.569 Δε (1 kHz, 20° C.)  --   --   --   --   --      .sup.ε ∥ (1 kHz, 20° C.)  --   --  --   --   --      d · Δn [μm] =       0.5  --   --   --   --   -- V.sub.(10,0,20) [V]  1.49   1.41   1.50      1.46   1.53 V.sub.(60,0,20) [V]  1.93   1.85   1.96   1.92   1.96      V.sub.(90,0,20) [V]  2.54   2.44   2.57   2.55   2.56 Composition [%]      PCH-5F 5.0  PCH-5F 5.0  PCH-5F 5.0  PCH-5F 5.0  PCH-5F 5.0  PCH-7F 6.0      PCH-7F 6.0  PCH-7F 6.0  PCH-7F 6.0  PCH-7F 6.0  CCP-20CF3 11.0  CCP-20CF3       11.0  CCP-20CF3 11.0  CCP-20CF3 11.0  CCP-20CF3 11.0  CCP-30CF3 12.0      CCP-30CF3 12.0  CCP-30CF3 12.0  CCP-30CF3 12.0  CCP-30CF3 12.0  CCP-40CF3       10.0  CCP-40CF3 10.0  CCP-40CF3 10.0  CCP-40CF3 10.0  CCP-40CF3 10.0      CCP-50CF3 12.0  CCP-50CF3 12.0  CCP-50CF3 12.0  CCP-50CF3 12.0  CCP-50CF3       12.0  BCH-3CF3.F.F 12.0  BCH-3CF3.F.F 12.0  BCH-3CF3.F.F 12.0  BCH-3F.F.      F 12.0  BCH-3F.F.F 12.0  BCH-5F.F.F 11.0  BCH-5F.F.F 11.0  BCH-5F.F.F      11.0  BCH-5CL.F.F 11.0  BCH-5F.F.F 11.0  CCP-3F.F.F 12.0  CCP-3F.F.F      12.0  CCP-3F.F.F 12.0  CCP-3F.F.F 12.0  CCP-3F.F.F 12.0  CCP-5F.F.F 9.0      CCP-5F.F.F 9.0  CCP-5F.F.F 9.0  CCP-5F.F.F 9.0  CCP-5F.F.F 9.0        example 98  99  100  101  102        Clearing Point [°C.]  +84   +86   +94   +98   +82  Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  --   --   --   --   -- Δn      (589 nm, 20° C.)  0.090   0.096   0.089   +0.087   +0.0936      n.sub.e (589 nm, 20° C.)  1.560   1.568   1.558   1.552   1.5707      Δε (1 kHz, 20° C.)  --   --   --   +4.8   --      .sup.ε ∥ (1 kHz, 20° C.)  --   --   --   8.1      -- d · Δn [μm] = 0.5  --   --   --   1.86   --      V.sub.(10,0,20) [V]  1.55   1.56   1.69   2.37   1.75 V.sub.(60,0,20)      [V]  1.99   1.98   2.15   3.12   2.71 V.sub.(90,0,20) [V]  2.55   2.55      2.78     PCH-5F 5.0 Composition [ %]    PCH-5F 5.0  PCH-5F 5.0      PCH-7F 6.0     PCH-7F 6.0  PCH-7F 6.0  CCH-3CF3 6.0  CCP-20CF3 11.0      CCP-20CF3 10.0  CCP-20CF3 11.0  CCP-20CF3 8.0  CCH-5CF3 6.0  CCP-30CF3      12.0  CCP-30CF3 11.0  CCP-30CF3 12.0  CCP-30CF3 9.0  CCP-20CF3 8.0      CCP-40CF3 10.0  CCP-40CF3 9.0  CCP-40CF3 10.0  CCP-40CF3 8.0  CCP-30CF3      8.0  CCP-50CF3 12.0  CCP-50CF3 11.0  CCP-50CF3 12.0  CCP-50CF3 9.0      CCP-40CF3 8.0  BCH-3F.F.F 12.0  BCH-3F.F.F 12.0  BCH-3F.F.F 12.0      CCP-50CF3 9.0  BCH-5F.F.F 11.0  BCH-5F.F.F 11.0  BCH-5F.F.F 11.0      CCP-3F.F 21.0  CCP-3F.F.F 12.0  CCP-3F.F.F 0.0  CCP-5F.F.F 9.0  CCP-5F.F.      F 0.0  CCP-3CL.F.F 12.0   CCH-3CF3 8.0  CCP-5CF3.F.F 21.0  CCP-5CL.F.F      11.0  CCP-3CL.F.F 12.0  CCH-5CF3 7.0     CCP-3CF3.F.F 16.0  CCP-5CL.F.F      11.0        CCP-5CF3.F.F 16.0  CCP-3CF3.F.F 16.0        CCP-5CF3.F.F      16.0  example 103 104 105 106 107 108          --  --  --  07.90  07.90     --  --  --  <-40  <-40  -- Clearing      Point [°C.]  74.3  72.8  69.8  +63  +64  +89  Viscosity [mm.sup.2      s.sup.-1 ] -20° C.  --  --  --  122  124  -- d ·      Δn (μm) = 0.4  --  --  --  cr. > 3 h  cr. < 3 h  Δn (589      nm, 20° C.)  0.1064  0.1076  0/1098  0.0873  0.800  +0.1019      n.sub.e (589 nm, 20° C.)  --  --  --  1.5669  1.5576  1.5801      Δε (1 kHz, 20°       C.)  --  --  --  --  --  -- .sup.ε ∥       (1 kHz, 20° C.)  --  --  --  --  --  -- V.sub.(10,0,20) [V]  --      --  --  1.51  1.61  1.66 V.sub.(60,0,20) [V]  --  --  --  1.93  2.04      2.11 V.sub.(90,0,20) [V]  --  --  --  2.52  2.66  2.74 Composition [%]:      PCH-5F 15.0 PCH-5F 14.2 PCH-5F 12.6 PCH-5F 10.0 PCH-5F 10.0 PCH-5F 10.0      PCH-7F 7.5 PCH-7F 7.1 PCH-7F 6.3 PCH-6F 7.0 PCH-6F 7.0  CCP-20CF3 5.6      CCP-20CF3 5.3 CCP-20CF3 4.7 PCH-7F 15.0 PCH-7F 10.0 PCH-7F 10.0      CCP-30CF3 11.2 CCP-30CF3 10.6 CCP-30CF3 9.4 CCP-20CF3 10.0 CCP-20CF3      10.0 CCP-20CF3 10.0  CCP-40CF3 3.7 CCP-40CF3 3.5 CCP-40CF3 3.1 CCP-30CF3      12.0 CCP-30CF3 12.0 CCP-30CF3 12.0  CCP-50CF3 9.2 CCP-50CF3 8.7 CCP-50CF3       7.8 CCP-40CF3 8.0 CCP-40CF3 8.0 CCP-40CF3 8.0  BCH-3F.F 21.4 BCH-3F.F      20.2 BCH-3F.F 18.0 CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3 12.0      BCH-5F.F 21.4 BCH-5F.F 20.2 BCH-5F.F 18.0 BCH-3F.F.F 10.0 CCP-3F.F.F      10.0  BCH-3F.F.F 5.0 BCH-3F.F.F 10.0 BCH-3F.F.F 20.0 BCH-5F.F 16.0      BCH-3F.F.F 15.0            BCH-5.FCF3 15.0            BCH-5.FCF3 15.0              CBC-33F 4.0            CBC-53F 4.0        example 109 110 111 112 113 114          --  --  --  --     Clearing Point [°C.]  +84  +86  +91  +101      +80  +78 Viscosity [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --  --      --  Sm d · Δn (μm) = 0.4 Δn (589 nm, 20°      C.)  +0.0880  +0.0976  +0.0916  +0.0934  +0.0756  0.0844 n.sub.e (589      nm, 20° C.)  1.5606  1.5695  1.5664  1.5608  1.5489  1.5610      Δε (1 kHz, 20°       C.)  --  --  --  --  --  -- .sup.ε ∥       (1 kHz, 20° C.)  --  --  --  --  --  -- V.sub.(10,0,20) [V]      1.76  1.70  1.72  1.90  1.66  1.61 V.sub.(60,0,20) [V]  2.24  2.17  2.21       2.42  2.12  2.06 V.sub.(90,0,20) [V]  2.89  2.76  2.87  3.07  2.73      2.72 Composition [%]: PCH-5F 10.0 PCH-5F 10.0 PCH-5F 7.0   PCH-5F 12.0      PCH-5F 12.0  PCH-7F 10.0   PCH-7F 7.0 PCH-7F 4.0 PCH-7F 8.0  CCP-20CF3      10.0 CCP-20CF3 10.0 CCP-20CF3 10.0 CCP-20CF3 10.0 CCP-20CF3 10.0      CCP-20CF3 10.0  CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3      12.0 CCP-30CF3 12.0 CCP-30CF3 12.0  CCP-40CF3 8.0 CCP-40CF3 8.0 CCP-40CF3       10.0 CCP-40CF3 8.0 CCP-40CF3 8.0 CCP-40CF3 8.0  CCP-50CF3 12.0 CCP-50CF3       12.0 CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3 12.0      BCH-3F.F.F 10.0   ECCP-3F.F 12.0 BCH-3F.F 8.0      BCH-5.FCF3 10.0      CCP-3F.F.F 14.0 BCH-5F.F 6.0  CCH-52CF3 15.0 CCH-32CF3 7.0   CCH-32CF3      10.0 CCP-5F.F.F 12.0 CCP-3F.F.F 13.0  BCH-3F.F.F 15.0 CCH-52CF3 7.0      CCH-52CF3 10.0   CCP-5F.F.F 12.0  BCH-5.FCF3 .0 BCH-3F.F.F 15.0 ECCP-3F.F       12.0 ECCP-3F.F 10.0  CBC-33F 4.0 BCH-5.FCF3 15.0 ECCP-5F.F 10.0      BCH-3F.F.F 12.0  CBC-53F 4.0 CBC-33F 4.0   BCH-5.FCF3 12.0        example 115 116 17 118 119 120 121                    --  -- Clearing Point [°C.]  +82  +75  +84  +88      +77  +83  +77 Viscosity [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --      --  --  --  -- d · Δn (μm) = 0.4 Δn (589 nm,      20° C.)  +0.0883  0.0876  +0.0908  +0.0925  0.0853  +0.0905      0.0837 n.sub.e (589 nm, 20° C.)  1.5519  1.5666  1.5655  1.5641      .5613  1.5575  1.5601 Δε (1 kHz, 20° C.)  --  --      --  --  --  --  -- .sup.ε ∥ (1 kHz, 20° C.)  --      --  --  --  --  --  -- V.sub.(10,0,20) [V]  1.82  1.51  1.65  1.74  1.64       1.68  1.71 V.sub.(60,0,20) [V]  2.29  1.95  2.13  2.21  2.12  2.14      2.17 V.sub.(90,0,20) [V]  2.89  2.54  2.76  2.84  2.75  2.75  2.76      Composition [%]:   PCH-5F 11.0 PCH-5F 11.0 PCH-5F 11.0 PCH-5F 12.0      PCH-5F 12.0    PCH-7F 9.0       CCH-32CF3 14.0  PCH-7F 4.0 CCP-20CF3 8.0      PCH-7F 7.0 PCH-7F 7.0 PCH-7F 10.0 CCH-52CF3 14.0 PCH-7F 10.0  CCP-20CF3      10.0 CCP-30CF3 10.0 CCP-20CF3 10.0 CCP-20CF3 10.0 CCP-20CF3 10.0      CCP-2CF3 10.0  CCP-30CF3 12.0 CCP-40CF3 7.0 CCP-30CF3 12.0 CCP-30CF3      12.0 CCP-30CF3 12.0   CCP-30CF3 12.0  CCP-40CF3 8.0 CCP-50CF3 10.0      CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3 8.0 CCP-20CF3 10.0 CCP-40CF3 8.0       CCP-50CF3 12.0 BCH-3F.F 10.0 CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3      12.0 CCP-30CF3 12.0 CCP-40CF3 8.0    BCH-5F.F 10.0 BCH-3F.F.F 10.0      BCH-3F.F.F 10.0 ECCP-3F.F 10.0 CCP-40CF3 8.0 CCP-50CF3 12.0  CCH-32CF3      15.0 CCP-3F.F.F 13.0 BCH-5.FCF3 10.0 BCH-5.FCF3 10.0 ECCP-5F.F 10.0      CCP-50CF3 12.0 ECCP-3F.F 10.0  CCH-52CF3 15.0 CCP-5F.F.F 12.0   ECCP-30CF      3 10.0 BCH-3F.F.F 8.0 BCH-3F.F.F 15.0 ECCP-5F.F 10.0        ECCP-50CF3      8.0 BCH-5F.F.F 8.0 BCH-5F.F.F 15.0    BCH-3F.F.F 12.0   ECCP-3F.F 10.0          BCH-5F.F.F 15.0  BCH-5.FCF3 12.0   ECCP-5F.F 8.0        example 122 123 124 125 126 127 128          --            --  Clearing Point [°C.]  +78  +86  +99  +74      +82  +83  +74.5 Viscosity [mm.sup.2 s.sup.-1 ] -20° C.  --  --      --  --  --  --  -- d · Δn (μm) = 0.4 Δn (589 nm,      20° C.)  0.0871  +0.0942  0.0840  +0.0867  0.0887  +0.0918      0.0893 n.sub.e (589 nm, 20° C.)  1.5644  .5675  1.5520  1.5643      1.5657  1.5697  1.5598 Δε (1 kHz, 20° C.)  --  +6.7       --  --  --  --  -- .sup.ε ∥ (1 kHz, 20° C.)  --       9.7  --  --  --  --  -- V.sub.(10,0,20) [V]  1.64  1.70  1.99  1.61      1.62  1.58  1.55 V.sub.(60,0,20)  [V]  2.0  2.18  2.51  2.04  2.10  2.02       1.99 V.sub.(90,0,20) [V]  2.68  2.82  3.22  2.62  2.73  2.61  2.57      Composition [%]: PCH-5F 14.0 PCH-5F 11.0 CCH-32CF3 2.0 PCH-5F 14.0      PCH-5F 11.0 PCH-5F 10.0 PCH-5F 8.0    PCH-7F 7.0 CCH-52CF3 12.0      PCH-7F 6.0 CCP-20CF3 10.0   PCH-7F 8.0 PCH-7F 7.0 PCH-7F 6.0  CCP-20CF3      10.0 CCP-30CF3 12.0 CCP-20CF3 10.0 CCP-20CF3 10.0 CCP-20CF3 10.0      CCP-20CF3 10.0 CCP-20CF3 10.0  CCP-30CF3 12.0 CCP-40CF3 10.0 CCP-30CF3      12.0 CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3 12.0      CCP-40CF3 8.0 CCP-50CF3 12.0 CCP-40CF3 8.0 CCP-40CF3 7.0 CCP-40CF3 10.0      CCP-40CF3 8.0 CCP-40CF3 8.0  CCP-50CF3 12.0 BCH-3F.F.F 10.0 CCP-50CF3      12.0 CCP-50CF3 11.0 CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3 12.0      ECCP-3F.F 10.0 BCH-5F.F.F 10.0 ECCP-3F.F 10.0 ECCP-3F.F 10.0 BCH-3F.F.F      10.0 BCH-3F.F.F 16.0  ECCP-5F.F 8.0 ECCP-30CF3 10.0 ECCP-5F.F 10.0      ECCP-5F.F 8.0 BCH-5F.F 10.0 BCH-5F.F.F 9.0  BCH-3F.F.F 8.0 ECCP-50CF3      8.0   BCH-3F.F.F 12.0 ECCP-3F.F 10.0 ECCP-3F.F 10.0 BCH-3F.F.F 15.0      BCH-5F.F.F 12.0   BCH-5F.F.F 16.0 BCH-5F.F.F 8.0 ECCP-5F.F 8.0 ECCP-5F.F      8.0 BCH-5F.F.F 15.0       12.0       CCH-32CF3 10.0       10.0      CCH-52CF3 10.0        example 129 130 131 132 133 134 135          --  --            Clearing Point [°C.]  +87  +75  +69  +85      +85  +85  +86 Viscosity [mm.sup.2 s.sup.-1 ]  --  150  --  --  160  --      -- -20° C. d · Δn (μm) = 0.4 Δn (589 nm,      20° C.)  +0.0938  +0874  +0.1233  +0.0910  +0.0914  +0.0910      +0.0931 n.sub.e (589 nm, 20° C.)  --  1.5650  1.6236  1.5684      1.5682  1.5679  1.5709 Δ ε (1 kHz, 20° C.)  --  --      --  --  --  --  -- .sup.ε ∥ (1 kHz, 20° C.)  --      --  --  --  --  --  -- V.sub.(10,0,20) [V]  1.58  1.55  1.13  1.60  n.d.       1.61  n.d. V.sub.(60,0,20) [V]  --  2.00  1.44  2.07  --  2.07  --      V.sub.(90,0,20) [V]  --  2.60  1.86  2.69  --  2.68  -- Composition [%]:      PCH-5F 9.0 PCH-5F 2.0 BCH-3F.F.F 30.0 PCH-5F 10.0 PCH-5F 8.0 PCH-5F 8.0      PCH-5F 9.0  PCH-7F 4.0   BCH-5F.F.F 60.0 PCH-7F 5.0 PCH-7F 7.0 PCH-7F      7.0  CCP-20CF3 10.0 PCH-7F 9.0 CBC-55F 10.0 CCP-20CF3 11.0 CCP-20CF3      12.0 CCP-20CF3 12.0 PCH-7F 5.0  CCP-30CF3 12.0 CCP-20CF3 11.0   CCP-30CF3       12.0 CCP-30CF3 14.0 CCP-30CF3 12.0 CCP-20CF3 10.0  CCP-40CF3 9.0      CCP-30CF3 12.0   CCP-40CF3 8.0 CCP-40CF3 9.0 CCP-40CF3 10.0 CCP-30CF3      12.0  CCP-50CF3 12.0 CCP-40CF3 7.0   CCP-50CF3 12.0 CCP-50CF3 12.0      CCP-50CF3 12.0 CCP-40CF3 9.0  BCH-3F.F.F 15.0 CCP-50CF3 11.0   BCH-3F.F.F       14.0 BCH-3F.F.F 14.0 BCH-3F.F.F 12.0 CCP-50CF3 12.0  BCH-5F.F.F 10.0      ECCP-3F.F 10.0   BCH-5F.F.F 9.0 BCH-5F.F.F 9.0 BCH-5F.F.F 11.0 BCH-3F.F.F       15.0  ECCP-3F.F 11.0 ECCP-5F.F 7.0   ECCP-3F.F 11.0 ECCP-3F.F 8.0      ECCP-3F.F 8.0 BCH-5F.F.F 10.0  ECCP-5F.F 8.0 BCH-3F.F.F 12.0   ECCP-5F.F      8.0 ECCP-5F.F 7.0 ECCP-5F.F 8.0 ECCP-3F.F 10.0    BCH-5F.F.F 9.0      ECCP-5F.F 8.0        example 136 137 138 139 140 141 142        Clearing Point [°C.]  +87  +86  +75  +75  +62  +88  +74      Viscosity [mm.sup.2 s.sup.-1 ]  --  --  --  --  --  --  -- -20°      C. d · Δn (μm) = 0.4              -- Δn (589 nm,      20° C.)  0.0915  +0.0905  +0.0870  +0.0876  +0.1264  +0.1353      +0.1298 n.sub.e (589 nm, 20° C.)  1.5680  1.5669  1.5645  1.5650      1.6296  1.6370  1.6319 Δε (1 kHz, 20° C.)  --  --      --  --  --  --  -- .sup.ε ∥ (1 kHz, 20° C.)  --      --  --  --  --  --  -- V.sub.(10,0,20) [V]  1.59  1.60  1.53  1.52  1.54       1.80  1.67 V.sub.(60,0,20) [V]  2.04  2.06  1.97  1.97  1.74  2.04      1.89 V.sub.(90,0,20) [V]  2.63  2.67  2.56  2.57  2.11  2.44  2.27      Composition [%]: PCH-5F 9.0   PCH-5F 7.0   BCH-3F.F 13.1 BCH-3F.F 12.0      BCH-3F.F 12.0    PCH-6F 9.0 PCH-6F 7.0 PCH-6F 12.0 BCH-5F.F 20.2      BCH-5F.F 18.0 BCH-5F.F 20.0  PCH-7F 6.0 PCH-7F 6.0 PCH-7F 7.0 PCH-7F 9.0      BCH-3F.F.F 22.7 BCH-3F.F.F 21.0 BCH-3F.F.F 23.0  CCP-20CF3 12.0 CCP-20CF3       12.0 CCP20CF3 11.0 CCP-20CF3 11.0 BCH-5F.F.F 44.0 BCH-5F.F.F 39.0      BCH-5F.F.F 40.0  CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3      12.0   CBC-33F 5.0  CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3 7.0 CCP-40CF3       7.0   CBC-55F 5.0 CBC-55F 5.0  CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3      11.0 CCP-50CF3 11.0  BCH-3F.F.F 12.0 BCH-3F.F.F 12.0 ECCP-3F.F 10.0      ECCP-3F.F 10.0  BCH-5F.F.F 10.0 BCH-5F.F.F 10.0 ECCP-5F.F 7.0 ECCP-5F.F      7.0  ECCP-3F.F 10.0 ECCP-3F.F 10.0 BCH-3F.F.F 12.0 BCH-3F.F.F 12.0      ECCP-5F.F 7.0 ECCP-5F.F 7.0 BCH-5F.F.F 9.0 BCH-5F.F.F 9.0        example 143 144 145 146 147 148                  --   Clearing Point [°C.]  +73  +85  +88  +77  +84      +84 Viscosity [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --  294  --      -- d · Δn (μm) = 0.4  -- Δn (589 nm, 20°      C.)  +0.0868  +0.0927  +0.0921  +0.1225  +0.0908  +0.0791 n.sub.e (589      nm, 20° C.)  1.5637  1.5709  1.5687  1.6198  1.5676  1.5494      Δε (1 kHz, 20°       C.)  --  --  --  --  --  -- .sup.ε ∥       (1 kHz, 20° C.)  --  --  --  --  --  -- V.sub.(10,0,20) [V]      1.45  1.81  1.60  2.21  1.57  1.78 V.sub.(60,0,20) [V]  1.87  2.32  2.05       2.59  2.00  2.28 V.sub.(90,0,20) [V]  2.43  3.02  2.66  2.98  2.59      2.97 Composition [%]: PCH-20F.F 10.0 PCH-5F 10.0 PCH-20F.F 5.0 PCH-5F      8.0 PCH-20F.F. 7.5 PCH-5F 10.0  PCH-40F.F 5.0 PCH-7F 5.0 PCH-40F.F 5.0      PCH-6F 8.0 PCH-40F.F 5.0    CCP-20CF3 11.0 CCP-20CF3 11.0 CCP-20CF3 11.0      PCH-7F 8.0 CCP-20CF3 11.0 PCH-7F 8.0  CCP-30CF3 12.0 CCP-30CF3 12.0      CCP-30CF3 12.0 FET-3F 6.0 CCP-30CF3 12.0 CCP-20CF3 10.0  CCP-40CF3 8.0      CCP-40CF3 8.0 CCP-40CF3 8.0 FET-5F 4.0 CCP-40CF3 8.0 CCP-30CF3 12.0      CCP-50CF3 12.0 CCP-50CF3 12.0 CCP-50CF3 12.0 CFET-3F.F 8.0 CCP-50CF3      12.0 CCP-40CF3 10.0  BCH-3F.F.F 14.0 BCH-20F.F 14.0 BCH-3F.F.F 14.0      BCH-3F.F.F 9.0 BCH-3F.F.F 14.0 CCP-50CF3 12.0  BCH-5F.F.F 9.0 BCH-5F.F.F      9.0 BCH-5F.F.F 9.0 BCH-5F.F.F 14.0 BCH-5F.F.F 9.0 ECCP-3F.F 12.0      EECP-3F.F 11.0 ECCP-3F.F 11.0 ECCP-3F.F 11.0 BCH-5F.F.F 13.0 ECCP-3F.F      11.0  ECCP-5F.F 8.0 ECCP-5F.F 8.0 ECCP-5F.F 13.0 BCH-52F 8.0 ECCP-5F.F      10.5        CBC-33F 2.0   CCP-3CF3.F.F 26.0        CBC-53F 3.0      CBC-55F 2.0        BCCP-30CF3 7.0        example 149 150 151 152 153 154              --  --  --  -- Clearing Point [ °C.]  +82  +87  +63  +89      +80  +91 Viscosity [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --  --      --  -- d · Δn (μm) = 0.4    -- Δn (589 nm,      20° C.)  +0.1210  +0.1260  +0.0816  +0.0927  +0.0779  +0.0945      n.sub.e (589 nm, 20° C.)  1.6180  1.6239  1.5575  1.5687  1.5486      1.5713 Δε (1 kHz, 20° C.)  --  --  --  --  --  --      .sup.ε ∥ (1 kHz, 20° C.)  --  --  --  --  --  --      V.sub.(10,0,20) [V]  2.25  2.33  1.55  1.61  1.64  1.71 V.sub.(60,0,20)      [V]  2.56  2.63  1.99  2.07  2.10  2.18 V.sub.(90,0,20) [V]  3.09  3.14      2.62  2.69  2.74  2.83 Composition [%]: PCH-5F 7.6 PCH-5F 7.6 PC-5F 10.0      PCH-5F 8.0 PCH-5F 12.0 PCH-5F 8.0  PCH-6F 7.6 PCH-6F 7.6 PCH-6F 7.0      PCH-7F 5.0   PCH-7F 5.0  PCH-7F 7.6 PCH-7F 7.6 PCH-7F 15.0 CCP-20CF3      10.0 PCH-7F 8.0 CCP-20CF3 10.0  FET-3F 5.7 FET-3F 5.7 CCP-20CF3 10.0      CCP-30CF3 12.0 CCP-20CF3 10.0 CCP-30CF3 12.0  FET-5F 3.8 FET-5F 3.8      CCP-30CF3 12.0 CCP-40CF3 8.0 CCP-30CF3 12.0 CCP-40CF3 8.0  CFET-3F.F 7.6      CFET-3F.F 7.6 CCP-40CF3 8.0 CCP-50CF3 10.0 CCP-40CF3 8.0 CCP-50CF3 10.0      BCH-3F.F.F 13.3 BCH-3F.F.F 13.3 CCP-3CF3.F.F 10.0 BCH-3F.F 10.0 CCP-50CF3       12.0 BCH-3F.F 10.0  BCH-6F.F.F 12.3 BCH-5F.F.F 12.3 BCH-5F.F 16.0      BCH-5F.F 10.0 ECCP-3F.F 12.0 BCH-5F.F 10.0  BCH-52F 7.6 BCH-52F 7.6      CBC-33F 1.9 CBC-33F 3.9   CCP-5F.F.F 9.0 CCP-5F.F.F 12.0 CCP-5F.F.F 9.0      CBC-53F 2.9 CBC-53F 3.9   ECCP-3F.F 6.0 CCP-3CF3.F.F 14.0 ECCP-3F.F 6.0      CBC-55F 1.9 CBC-55F 3.9   CCP-3CF3.F.F 12.0   CCP-3CF3.F 12.0  ECCP-30CF3       6.7 ECCP-30CF3 6.7  CP-4F 5.0        example 155 156 157 158 159 160           --    --       Clearing Point [°C.]  +82  +90  +86  +91  +88       +86 Viscosity [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --  --  --      -- d · Δn (μm) = 0.4 Δn (589 nm, 20° C.)      +0.0776  +0.0960  +0.1379  +0.0900  +0.0945  +0.1370 n.sub.e (589 nm,      20°       C.)  1.5491  1.5710  1.6417  1.5640  1.5655  1.6405 Δε (1      kHz, 20° C.)  --  --  --  --  --  -- .sup.ε ∥ (1      kHz, 20° C.)  --  --  --  --  --  -- V.sub.(10,0,20) [V]  1.73      1.66  2.19  1.65  1.59  2.05 V.sub.(60,0,20) [V]  2.22  2.10  2.47  2.12       2.05  2.33 V.sub.(90,0,20) [V]  2.88  2.71  2.96  2.75  2.68  2.82      Composition [%]: PCH-5F 12.0 PCH-5F 8.0 PCH-5F 5.0 PCH-50CF3 13.0      PCH-30CF3 9.0 PCH-5F 5.0    PCH-7F 5.0 PCH-6F 8.0   PCH-50CF3 6.0 PCH-6F      8.0  PCH-7F 8.0 CCP-20CF3 10.0 PCH-7F 4.0 CCP-20CF3 10.0 CCP-20CF3 12.0      PCH-7F 4.0  CCP-20CF3 10.0 CCP-30CF3 12.0 FET-3F 8.0 CCP-30CF3 12.0      CCP-30CF3 12.0 FET-3F 8.0  CCP-30CF3 12.0 CCP-40CF3 8.0 FET-5F 7.0      CCP-40CF3 8.0 CCP-40CF3 10.0 FET-5F 7.0  CCP-40CF3 8.0 CCP-50CF3 10.0      CFET-3F.F 10.0 CCP-50CF3 10.0 CCP-50CF3 12.0 CFET-3F.F 10.0  CCP-50CF3      12.0 BCH-3F.F 10.0 CFET-5F.F 12.0 BCH-3F.F 10.0 BCH-3F.F.F 12.0 CFET-5F.F       9.0  ECCP-3F.F 12.0 BCH-5F.F 10.0 BCH-3F.F 12.0 BCH-5F.F 10.0 BCH-5F.F.F       10.0 BCH-3F.F 12.0    CCP-3CF3.F 9.0 BCH-5F.F 12.0 CCP-3F.F.F 12.0      ECCP-3F.F 10.0 BCH-5F.F 12.0  CCP-5F.F.F 12.0 ECCP-3F.F 6.0 BCH-3F.F.F      6.0 CCP-5F.F.F 9.0 ECCP-5F.F 7.0 BCH-3F.F.F 6.0  CCP-3CF3.F 14.0      CCP-3CF3.F.F 12.0 BCH-5F.F.F 12.0 ECCP-3F.F 6.0   BCH-5F.F.F 12.0      CBC-33F 2.0     CBC-33F 2.0      CBC-53F 3.0     CBC-53F 3.0      CBC-55F 2.0     CBC-55F 2.0        example 161 162 163 164 165 166        Clearing Point [°C.]  +85  +82  +93  +79  +86  +91 Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  530  --  590  1050  --  -- d      · Δn (μm) = 0.4 Δn (589 nm, 20° C.)      +0.1360  +0.0928  +0.1395  +0.1375  +0.0932  +0.0937 n.sub.e (589 nm,      20°       C.)  1.6395  1.5681  1.6430  1.6400  1.5682  1.5705 Δε (1      kHz, 20° C.)  --  --  --  --  --  -- .sup.ε ∥ (1      kHz, 20° C.)  --   --  --  --  --  -- V.sub.(10,0,20) [V]  2.00      1.55  2.13  1.49  1.58  1.56 V.sub.(60,0,20) [V]  2.27  1.98  2.43  1.69       2.03  2.02 V.sub.(90,0,20) [V]  2.72  2.56  2.90  2.01  2.65  2.61      Composition [%]: PCH-5F 5.0 PCH-3CF3 13.0 PCH-5F 6.0 BCH-3F.F.F 30.0      PCH-5CF3 13.0 PCH-6F 8.0  PCH-6F 8.0   PCH-6F 9.0 BCH-5F.F.F 50.0      PCH-7F 5.0  PCH-7F 4.0 CCP-20CF3 10.0 FET-3F 7.0 CFET-3F.F 10.0 CCP-20CF3       10.0 CCP-20CF3 10.0  FET-3F 7.0 CCP-30CF3 12.0 FET-5F 7.0 CFET-5F.F      10.0 CCP-30CF3 12.0 CCP-30CF3 12.0  FET-5F 7.0 CCP-40CF3 8.0 CFET-3F.F      10.0   CCP-40CF3 8.0 CCP-40CF3 8.0  CFET-3F.F 10.0 CCP-50CF3 10.0      CFET-5F.F 10.0   CCP-50CF3 10.0 CCP-50CF3 10.0  CFET-5F.F 10.0 BCH-3F.F      10.0 BCH-3F.F 10.0   BCH-3F.F 10.0 BCH-3F.F 10.0  BCH-3F.F 10.0 BCH-5F.F      10.0 BCH-5F.F 10.0   BCH-5F.F 10.0 BCH-5F.F 10.0  BCH-5F.F 10.0 CCP-3F.F.      F 12.0 BCH-3F.F.F 12.0   CCP-3F.F.F 12.0 CCP-3F.F.F 12.0  BCH-3F.F.F.F      12.0 CCP-5F.F.F 9.0 BCH-5F.F.F 10.0   CCP-5F.F.F 9.0  BCH-5F.F.F 10.0      ECCP-3F.F 6.0 CBC-33F 3.0   ECCP-3F.F 6.0 ECCP-3F.F 6.0  CBC-33F 2.0      CBC-53F 3.0     CCP-5CF3.F.F 9.0  CBC-55F 3.0   CBC-55F 3.0  CBC-55F      2.0   example 167 168 169 170 171 172                --  --   Clearing Point [°C.]  +91  +81  +86  +61.5      +87  +64.5 Viscosity [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --  --       --  -- d · Δn (μm) = 0.4 Δn (589 nm, 20°      C.)  +0.0875  +0.0841  +0.0858  +0.0637  +0.0949  +0.0652 n.sub.e (589      nm, 20° C.)  1.5591  1.5573  1.5586  1.5380  1.5672  1.5338      Δε (1 kHz, 20°       C.)  --  --  --  --  --  -- .sup.ε ∥       (1 kHz, 20° C.)  --  --  --  --  --  -- V.sub.(10,0,20) [V]      1.59  1.50  1.57  2.49  1.54  1.68 V.sub.(60,0,20) [V]  2.06  1.94  2.04       3.00  1.98  2.14 V.sub.(90,0,20) [V]  2.66  2.52  2.63  3.84  2.58      2.77 Composition [%]: PCH-5F 8.0 PCH-5F 10.0 PCH-5F 12.0 CCP-3F.F.F 8.0      PCH-5F 5.0 PCH-5F 7.0  PCH-7F 8.0 PCH-7F 11.0 PCH-7F 6.0 CCP-5F.F.F 8.0      PCH-7F 6.0 PCH-7F 7.0  CCP-20CF3 10.0 CCP-20CF3 8.0 CCP-20CF3 12.0      CCP-20CF3 8.0 CCP-20CF3 11.0 PCH-302 6.0  CCP-30CF3 10.0 CCP-30CF3 9.0      CCP-30CF3 12.0 CCP-30CF3 .0 CCP-30CF3 12.0 CCH-3CF3 12.0  CCP-40CF3 10.0      CCP-40CF3 9.0 CCP-40CF3 7.0 CCP-40CF3 8.0 CCP-40CF3 10.0 CCH-5CF3 12.0      CCP-50CF3 10.0 CCP-50CF3 9.0 CCP-50CF3 7.0 CCP-50CF3 .0 CCP-50CF3 12.0      CCP-3F.F.F 10.0  CCP-5CF3.F.F 15.0 CCP-5CF3.F.F 15.0 CCP-5CF3.F.F 15.0      CCH-301 9.01 BCH3.FCF3 12.0 CCP-5F.F.F 9.0  CCP-3CL.F.F 15.0 CCP-3CL.F.F      15.0 CCP-3CL.F.F 15.0 CCH-302 9.0 BCH-5.FCF3 11.0 CCP-30CF3 10.0      CCP-5CL.F.F 14.0 CCP-5CL.F.F 14.0 CCP-5CL.F.F 14.0 CCH-303 8.0 CCP-3F.F.F       12.0 CCP-50CF3 9.0        CCH-501 8.0 CCP-5F.F.F 9.0 CP-3F 6.0      CCH-502 8.0   CP-4F 6.0        PCH-301 8.0   CP-5F 6.0        PCH-302      7.0        PCH-501 7.0        CCPC-36 4.0        example 173 174 175 176 177 178        Clearing Point [°C.]  +89  +97  +98.7  +84  +96  +89.2 Viscosity       [mm.sup.2 s.sup.-1 ] -20°       C.  --  --  --  --  --  -- d · Δn (μm) = 0.4 Δn      (589 nm, 20° C.)  +0.0965  +0.0994  0.1343  +0.1354  +0.1097      +0.0921 n.sub.e (589 nm, 20° C.)  1.5562  1.5790  1.6330  1.6385      1.5872  1.5703 Δε (1 kHz, 20° C.)  --  --  5.97  --       --  -- .sup.ε ∥ (1 kHz, 20° C.)  --  --  9.99      --  --  -- V.sub.(10,0,20) [V]  1.47  1.67  --  1.99  1.45  1.62      V.sub.(60,0,20) [V]  1.91  2.15  --  2.28  1.86  2.10 V.sub.(90,0,20)      [V]  2.49  2.80  --  2.84  2.40  2.72 Composition [%]: PCH-5F 4.0 PCH-5F      5.0 BCH-3CL.F.F 41.0 PCH-5F 5.0 PCH-5F 10.0 PCH-5F 8.0  PCH-7F 5.0      PCH-7F 6.0 BCH-5CL.F.F 59.0 PCH-6F 8.0 PCH-7F 10.0 PCH-7F 5.0  CCP-20CF3      14.0 CCP-20CF3 11.0   PCH-7F 4.0 CCP-20CF3 10.0 CCP-20CF3 10.0  CCP-30CF3       14.0 CCP-30CF3 12.0   FET-3F 7.0 CCP-30CF3 12.0 CCP-30CF3 12.0      CCP-40CF3 14.0 CCP-40CF3 10.0   FET-5F.F 7.0 CCP-40CF3 8.0 CCP-40CF3 8.0       CCP-50CF3 15.0 CCP-50CF3 12.0   CFET-3F.F 10.0 CCP-50CF3 12.0 CCP-50CF3      10.0  CUP-3F.F 11.0 BCH-3F.F 15.0   CFET-5F.F 10.0 BCH-5F.F.F 6.5      BCH-3F.F 10.0  CUP-4.F.F 4.0 BCH-5F.F 15.0   BCH-3F.F 10.0 BCH-3F.F.F      8.6 BCH-5F.F 10.0  CCP-3F.F.F 10.0 CCP-3DF.F.F 8.0   BCH-5F.F 10.0      BCH-5.FCF3 15.0 CCP-3F.F.F 12.0  CCP-5F.F.F 9.0 CCP-5F.F.F 6.0      BCH-3F.F.F 12.0 CP-4F 8.0 CCP-5F.F.F 9.0        BCH-5F.F.F 10.0      ECCP-3F.F 6.0        CBC-33F 10.0        CBC-53F 3.0        CBC-55F      2.0    example 179 180 181 182 183 184        Clearing Point [°C.]  +73  +80  +82  +89  +80  +89 Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  --  --  --  --  --  -- d ·      Δn (μm) = 0.5 Δ n (589 nm, 20° C.)  +0.0880      +0.0990  +0.0858  0.098  +0.0877  +0.0903 n.sub.e (589 nm, 20°      C.)  1.5641  1.5794  1.5609  1.574  1.5621  1.5590 Δε (1      kHz, 20° C.)  --  --  --  --  --  -- .sup.ε ∥ (1      kHz, 20° C.)  --  --  --  --  --  -- V.sub.(10,0,20) [V]  1.64      1.63  1.74  1.61  1.56  1.60 V.sub.(60,0,20) [V]  2.03  2.03  2.12  2.06       1.91  2.03 V.sub.(90,0,20) [V]  2.60  2.60  2.71  2.69  2.43  2.63      Composition [%]: PCH-5F 5.0 PCH-5F 10.0 PCH-5F 5.0 PCH-5F 6.3 PCH-5F 5.0      PCH-5F 5.0  PCH-6F 13.0 PCH-7F 10.0 PCH-6F 9.0 PCH-7F 7.6 PCH-7F 6.0      PCH-7F 6.0  PCH-7F 7.0 CCP-20CF3 8.0 PCH-7F 7.0 CCP-20CF3 13.9 CCP-20CF3      11.0 CCP-20CF3 11.0  CCP-20CF3 10.0 CCP-30CF3 10.0 CCP-20CF3 10.0      CCP-30CF3 15.2 CCP-30CF3 12.0 CCP-30CF3 12.0  CCP-30CF3 11.0 CCP-40CF3      8.0 CCP-30CF3 11.0 CCP-40CF3 12.7 CCP-40CF3 10.0 CCP-40CF3 10.0      CCP-40CF3 10.0 CCP-50CF3 10.0 CCP-40CF3 10.0 CCP-50CF3 15.2 CCP-50CF3      12.0 CCP-50CF3 12.0  CCP-50CF3 12.0 BCH-3F.F 8.0 CCP-50CF3 12.0 BCH-3F.F.      F 15.2 CUP-3F.F 12.0 CUP-30CF3 12.0  BCH-3F.F.F 12.0 BCH-5F.F 8.0      BCH-3F.F.F 12.0 BCH-5F.F 13.9 CUP-5F.F 11.0 CUP-50CF3 11.0  BCH-5F.F.F      12.0 BCH-3F.F.F 10.0 BCH-5F.F.F 12.0   CCP-3F.F.F 12.0 CCP-3F.F.F 12.0      CP-30CF3 4.0 BCH-5F.F.F 10.0 CP-30CF3 6.0   CCP-5F.F.F 9.0 CCP-5F.F.F      9.0  CF-50CF3 4.0 CP-30CF3 4.0 CP-50CF3 6.0    CP-50CF3 4.0        example 185 186 187 188 189 190        Clearing Point [°C.]  +95  +86  +85  129.3  +84  +98 Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  --  --  kr < 1 h  -- d ·      Δn (μm) = 0.5 Δn (589 nm, 20° C.)  +0.0970      +0.0950  +0.0958  0.0838  +0.0904  0.089 n.sub.e (589 nm, 20° C.)       1.5679  1.5708  1.5583  1.5395  1.5618  1.559 Δε (1 kHz,      20° C.)  --  --  --  +8.74  --  -- .sup.ε ∥ (1      kHz, 20° C.)  --  --  --  12.7  --  -- V.sub.(10,0,20) [V]  1.73      1.58  1.59  --  1.51  1.76 V.sub.(60,0,20) [V]  2.15  1.98  1.96  --      1.88  2.24 V.sub.(90,0,20) [V]  2.77  2.58  2.44  --  2.38  2.89      Composition [%]: PCH-5F 5.0 PCH-5F 5.0 PCH-5F 5.0 CCP-30CF2.F.F 34.0      PCH-5F 5.0 PCH-5F 5.0  PCH-7F 6.0 PCH-7F 6.0 PCH-7F 6.0 CCP-50CF2.F.F      66.0 PCH-7F 6.0 PCH-7F 6.0  CCP-20CF3 11.0 CCP-20CF3 11.0 CCP-20CF3 11.0        CCP-20CF3 11.0 CCP-20CF3 11.0  CCP-30CF3 12.0 CCP-30CF3 12.0 CCP-30CF3      12.0   CCP-30CF3 12.0 CCP-30CF3 12.0  CCP-40CF3 10.0 CCP-40CF3 10.0      CCP-40CF3 10.0   CCP-40CF3 10.0 CCP-40CF3 10.0  CCP-50CF3 12.0 CCP-50CF3      12.0 CCP-50CF3 12.0   CCP-50CF3 12.0 CCP-50CF3 12.0  CUP-30CF3 12.0      CUP-3F.F 12.0 CUP-30CF3 12.0   CUP-3F.F 12.0  CUP-50CF3 11.0 CUP-5F.F      11.0 CUP-50CF3 11.0   CUP-5F.F 11.0  CCP-3CL.F.F 12.0 CCP-3CL.F.F 12.0      CCP-3CF3.F.F 12.0   CCP-30CF2.F.F 12.0  CCP-5CL.F.F 9.0 CCP-5CL.F.F 9.0      CCP-5CF3.F.F 9.0   CCP-50CF2.F.F 9.0            CCP-3CL.F.F 12.0         CCP-5CL.F.F 11.0            CCP-3CF3.F.F 12.0            CCP-5CF3.F.F      9.0        example 191 192 193 194 195        Clearing Point [°C.]  +98  +97  +80  +96  +97 Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.        ce 2 < sm < 3  ce 74 < kr <      98 d · Δn (μm) = 0.5    --  -- Δn (589 nm,      20° C.)  --  +0.0920  +0.0892  +0.0846  +0.0900 n.sub.e (589 nm,      20° C.)  --  1.5586  1.5569  1.5492  1.5609 Δε (1      kHz, 20° C.)  --  --  --  --  -- .sup.ε ∥ (1      kHz, 20° C.)  --  --  --  --  -- V.sub.(10,0,20) [V]  --  1.66      1.62  1.83  1.67 V.sub.(60,0,20) [V]  --  2.05  2.02  2.26  2.06      V.sub.(90,0,20) [V]  --  2.57  2.60  2.89  2.66 Composition [%]: PCH-5F      5.0 PCH-5F 5.0 PCH-5F 8.0 PCH-5F 5.0 PCH-5F 8.0  PCH-7F 6.0 PCH-7F 5.0      PCH-7F 8.0 PCH-7F 6.0 CCP-20CF3 9.0  CCP-20CF3 11.0 CCP-20CF3 11.0      CCP-20CF3 9.0 CCP-20CF3 11.0 CCP-30CF3 11.0  CCP-30CF3 12.0 CCP-30CF3      11.0 CCP-30CF3 10.0 CCP-30CF3 12.0 CCP-40CF3 10.0  CCP-40CF3 10.0      CCP-40CF3 10.0 CCP-40CF3 9.0 CCP-40CF3 10.0 CCP-50CF3 11.0  CCP-50CF3      12.0 CCP-50CF3 9.0 CCP-50CF3 10.0 CCP-50CF3 12.0 CUP-3F.F 10.0  CCP-3CF3.      F.F 12.0 CUP-30CF3 12.0 CUP-30CF3 12.0 CCP-3CF3.F.F 12.0 CUP-5F.F 11.0      CCP-5CF3.F.F 11.0 CUP-50CF3 12.0 CUP-50CF3 11.0 CCP-5CF3.F.F 11.0      CCP-30CF2.F.F 12.0  CCP-3CL.F.F 12.0 CCP-30CF2.F.F 10.0 CCP-30CF2.F.F      12.0 CCP-30CF2.F.F 12.0 CCP-50CF2.F.F 12.0  CCP-5CL.F.F 9.0 CCP-50CF2.F.F       11.0 CCP-50CF2.F.F 11.0 CCP-50CF2.F.F 9.0 CH-33 6.0    CH-33 4.0        example 196 197 198 199 200        Clearing Point [°C.]  +103  +98  +98  +95  +91 Viscosity      [mm.sup.2 s.sup.-1 ] -20° C.  ce 91 < sm < 99  --  --  744h?  24      < kr < 42 d · Δn (μm) =       0.5 Δn (589 nm, 20° C.)  +0913  +0.0921  +0.0910  +0.0941      0.0934 n.sub.e (589 nm, 20° C.)  1.5603  1.5591  1.5570  1.5666      1.5648 Δε (1 kHz, 20° C.)  --  --  --  --  --      .sup.ε ∥ (1 kHz, 20° C.)  --  --  --  --  --      V.sub.(10,0,20) [V]  1.67  1.59  1.59  1.54  1.48 V.sub.(60,0,20) [V]      2.05  2.02  2.02  1.97  1.91 V.sub.(90,0,20) [V]  2.56  2.61  2.62  2.58       2.50 Composition [%]: PCH-5F 8.0 PCH-5F 5.0 PCH-5F 5.0 PCH-5F 5.0      PCH-5F 5.0  CCP-20CF3 9.0 PCH-7F 5.0 PCH-7F 6.0 PCH-7F 5.0 PCH-7F 5.0      CCP-30CF3 10.0 CCP-20CF3 9.0 CCP-20CF3 9.0 CCP-20CF3 9.0 CCP-20CF3 9.0      CCP-40CF3 9.0 CCP-30CF3 11.0 CCP-30CF3 10.0 CCP-30CF3 11.0 CCP-30CF3      11.0  CCP-50CF3 12.0 CCP-40CF3 10.0 CCP-40CF3 9.0 CCP-40CF3 10.0      CCP-40CF3 10.0  CUP-3F.F 9.0 CCP-50CF3 11.0 CCP-50CF3 10.0 CCP-50CF3      11.0 CCP-50CF3 11.0  CUP-5F.F 9.0 CUP-30CF3 12.0 CUP-30CF3 10.0 CUP-3F.F      11.0 CUP-3F.F 11.0  CCP-30CF2.F.F 10.0 CUP-50CF3 12.0 CUP-50CF3 9.0      CUP-5F.F 10.0 CUP-5F.F 10.0  CCP-50CF2.F.F 10.0 CCP-30CF2.F.F 10.0      CCP-30CF2.F.F 12.0 CCP-30CF2.F.F 12.0 CCP-30CF2.F.F 12.0  CP-30CF3 7.0      CCP-50CF2.F.F 11.0 CCP-50CF2.F.F 12.0 CCP-50CF2.F.F 12.0 CCP-50CF2.F.F      12.0  CP-50CF3 7.0 CH-33 4.0 CP-30CF3 8.0 CBC-33F 4.0 CCUP-3F.F 4.0        example 201 202 203 204 205 206        Clearing Point [°C.]  +92  +95  +95  +93  107  +83 Viscosity      [mm.sup.2 s.sup.-1 ]  24 < kr < 42      --  49 <  -- -20° C.          kr < 120 d · Δn (μm) = 0.5 Δn (589 nm,      20° C.)  +0.0933  +0.0921  +0.0917  +0.1404  +0.0870  +0.0881      n.sub.e (589 nm, 20° C.)  1.5643  1.5638  1.5637  1.6420  1.5564      1.5561 Δε (1 kHz, 20° C.)  --  --  --   +11.6  --      -- .sup.ε ∥ (1 kHz, 20° C.)  --  --  --  15.7      --  -- V.sub.(10,0,20) [V]  1.49  1.55  1.53  1.25  1.88  1.47 V.sub.(60,      0,20) [V]  1.91  1.99  1.96  1.58  2.31  1.82 V.sub.(90,0,20) [V]  2.51      2.61  2.54  2.05  2.88  2.27 Composition [%]: PCH-5F 5.0 PCH-5F 5.0      PCH-5F 5.0 BCH-3F.F 12.0 PCH-5F 5.0 PCH-5F 5.0  PCH-7F 5.0 PCH-7F 5.0      PCH-7F 5.0 CFET-5F.F.F 20.0 PCH-7F 6.0 PCH-7F 6.0  CCP-20CF3 9.0      CCP-20CF3 9.0 CCP-20CF3 9.0 BCH-3F.F.F 23.0 CCP-20CF3 11.0 CCP-20CF3      11.0  CCP-30CF3 11.0 CCP-30CF3 11.0 CCP-30CF3 11.0 BCH-5F.F.F 40.0      CCP-30CF3 12.0 CCP-30CF3 12.0  CCP-40CF3 10.0 CCP-40CF3 10.0 CCP-40CF3      10.0 CBC-55F 5.0 CCP-40CF3 10.0 CCP-40CF3 10.0  CCP-50CF3 11.0 CCP-50CF3      11.0 CCP-50CF3 11.0   CCP-50CF3 12.0 CCP-50CF3 12.0  CUP-3F.F 11.0      CUP-3F.F 11.0 CUP-3F.F 11.0   CCP-3CL.F.F 12.0 CUP-30CF3.F 12.0      CUP-5F.F 10.0 CUP-5F.F 10.0 CUP-5F.F 10.0   CCP-5CL.F.F 11.0 CUP-50CF3.F      11.0  CCP-30CF2.F.F 12.0 CCP-30CF2.F.F 12.0 CCP-30CF2.F.F 12.0      CCP-30CF2.F.F 12.0 CCP-3F.F.F 12.0  CCP-50CF2.F.F 12.0 CCP-50CF2.F.F      12.0 CCP-50CF2.F.F 12.0   CCP-50CF2.F.F 9.0 CCP-5F.F.F 9.0  CCUP-30CF3      4.0 CCEPC-35 4.0 CCEPC-53 4.0        example 207 208 209 210 211 212        Clearing Point [°C.]  +128  +80  +81  +92  +104  +94 Viscosity      [mm.sup.2 s.sup.-1 ]  --  kr < 15  432 h?  744 h?  744 h?  744 h?      -20° C. d · Δn (μm) = 0.5 Δn (589 nm,      20° C.)  +0.089  +0.0870  +0.0874  +0.0913  +0.0953  +0.0875      n.sub.e (589 nm, 20° C.)  1.554  1.5601  1.5610  1.5654  1.5713      1.5590 Δε (1 kHz, 20° C.)  --  --  --  --  --  --      .sup.ε ∥ (1 kHz, 20° C.)  --  --  --  --  --  --      V.sub.(10,0,20) [V]  1.95  1.68  1.70  1.63  1.72  1.72 V.sub.(60,0,20)      [V]  2.35  2.08  2.11  2.01  2.13  2.15 V.sub.(90,0,20) [V]  3.01  2.71      2.74  2.53  2.69  2.81 Composition [%]: CCP-30CF2.F.F 34.0 PCH-5F 10.0      PCH-301 4.0 PCH-5F 5.0 PCH-5F 5.0 PCH-5F 5.0  CCP-50 CF2.F.F 66.0 PCH-7F      10.0 PCH-5F 9.0 PCH-7F 5.0 CH-7F 5.0 PCH-7F 5.0    CCP-20CF3 9.0 PCH-7F      9.0 CCP-20CF3 8.0 CCP-20CF3 8.0 CCP-20CF3 8.0    CCP-30CF3 11.0 CCP-20CF3       9.0 CCP-30CF3 9.0 CCP-30CF3 8.0 CCP-30CF3 9.0    CCP-40CF3 10.0      CCP-30CF3 11.0 CCP-50CF3 9.0 CCP-50CF3 8.0 CCP-50CF3 9.0    CCP-50CF3      11.0 CCP-40CF3 10.0 ECCP-3F.F 8.0 ECCP-3F.F 8.0 ECCP-3F.F 8.0      CUP-3F.F 8.0 CCP-50CF3 11.0 ECCP-5F.F 8.0 ECCP-5F.F 8.0 ECCP-5F.F 8.0      CUP-5F.F 7.0 CUP-3F.F 7.0 CUP-3F.F 9.0 CUP-3F.F 8.0 CUP-3F.F 7.0      CCP-30CF2.F.F 10.0 CUP-5F.F 7.0 CUP-5F.F 9.0 CUP-5F.F 8.0 CUP-5F.F 7.0       CCP-50CF2.F.F 10.0 CCP-30CF2.F.F 10.0 CCP-30CF2.F.F 12.0 CCP-30CF2.F.F      10.0 CCP-30CF2.F.F 11.0    CBC-33F 4.0 CCP-50CF2.F.F 9.0 CCP-50CF2.F.F      15.0 CCP-50CF2.F.F 15.0 CCP-50CF2.F.F 17.0      CBC-33F 4.0 CBC-33F 3.0      CBC-33F 3.0 CP-30CF3 3.0          CBC-53F 3.0 CP-50CF3 3.0      CBC-55F 3.0        example 213 214 215 216 217 218        Clearing Point [°C.]  +100  +102  +107  +99  +100  +99 Viscosity       [mm.sup.2 s.sup.-1 ]  240 h?  240 h?  2 h <  240 h?  216 h?  350      -20° C.      sm < 3 h d · Δn (μm) = 0.5      Δn (589 nm, 20° C.)  +0.0896  +0.0925  +0.0841  +0.0838      +0.0907  +0.1064 n.sub.e (589 nm, 20° C.)  1.5686  1.5700  1.5618       1.5551  1.5692  1.5903 Δε (1 kHz, 20° C.)  --  --      --  --  --  +6.7 .sup.ε ∥ (1 kHz, 20° C.)  --      --  --  --  --  10.3 V.sub.(10,0,20) [V]  1.97  1.86  --  1.88  1.88      1.82 V.sub.(60,0,20) [V]  2.45  2.30  --  2.33  2.32  2.23 V.sub.(90,0,20      ) [V]  3.17  2.92  --  3.01  2.94  2.89 Composition [%]: PCH-5F 8.0      PCH-301 5.0 PCH-5F 4.0 PCH-5F 6.0 PCH-5F 7.0 PCH-5F 7.0  PCH-7F 7.0      PCH-5F 5.0 PCH-7F 4.0 PCH-7F 6.0 PCH-7F 7.0 PCH-7F 6.0  CCP-20CF3 5.0      PCH-7F 5.0 CCP-20CF3 5.0 CCP-20CF3 8.0 CCP-20CF3 5.0 CCP-20CF3 5.0      CCP-30CF3 6.0 CCP-20CF3 8.0 CCP-30CF3 7.0 CCP-30CF3 9.0 CCP-30CF3 6.0      CCP-30CF3 6.0  CCP-50CF3 6.0 CCP-30CF3 8.0 CCP-50CF3 7.0 CCP-50CF3 9.0      CCP-50CF3 6.0 CCP-50CF3 6.0  ECCP-3F 7.0 CCP-50CF3 8.0 ECCP-3F 12.0      ECCP-3F.F 11.0 ECCP-3F 8.0 ECCP-3F 8.0  ECCP-5F 7.0 ECCP-3F.F 11.0      ECCP-5F 12.0 ECCP-5F.F 10.0 ECCP-3F.F 11.0 BCH-3F.F 11.0  ECCP-3F.F 8.0      ECCP-5F.F 10.0 ECCP-3F.F 11.0 CUP-3F.F 4.0 ECCP-5F.F 11.0 BCH-5F.F 11.0      ECCP-5F.F 7.0 CUP-3F.F 6.0 ECCP-5F.F 11.0 CUP-5F.F 3.0 CUP-3F.F 6.0      CUP-3F.F 6.0  CUP-3F.F 6.0 CUP-5F.F 5.0 CUP-3F.F 4.0 CCP-30CF2.F.F 8.0      CUP-5F.F 5.0 CUP-5F.F 5.0  CUP-5F.F 5.0 CCP-30CF2.F.F 7.0 CUP-5F.F 3.0      CCP-50CF2.F.F 14.0 CCP-30CF2.F.F 7.0 CCP-30CF2.F.F 7.0  CCP-30CF2.F.F      7.0 CCP-50CF2.F.F 13.0 CCP-30CF2.F.F 7.0 CP-20CF3 4.0 CCP-50CF2.F.F 13.0      CCP-50CF2.F.F 13.0  CCP-50CF2.F.F 13.0 CBC-33F 3.0 CCP-50CF2.F.F 13.0      CP-30CF3 4.0 CBC-33F 4.0 CBC-33F 3.0  CBC-33F 4.0 CBC-53F 3.0   CP-50CF3      4.0 CBC-53F 4.0 CBC-53F 3.0  CBC-53F 4.0 CBC-55F 3.0       CBC-55F      3.0     example 219 220 221 222 223 224        Clearing Point [°C.]  +88  +101  +93  +99  +101  +103 Viscosity      [mm.sup.2 s.sup.-1 ]  216 h?  168 h?  168 h?  168 h?  168 h?  168 h      -20° C. d · Δn (μm) = 0.5 Δn (589 nm,      20° C.)  +0.0813  +0.085  --  +0.0951  +0.0913  +0.0960 n.sub.e      (589 nm, 20° C.)  1.5536  1.5560  --  1.5761  1.5690  1.5756      Δε (1 kHz, 20° C.)  --  +7.2  --  --  --  --      .sup.ε ∥ (1 kHz, 20° C.)  --  10.8  --  --  --      -- V.sub.(10,0,20) [V]  1.85  1.77  --  1.90  1.84  1.90 V.sub.(60,0,20)      [V]  2.28  2.20  --  2.34  2.28  2.38 V.sub.(90,0,20) [V]  2.96  2.77      --  2.96  2.89  3.09 Composition [%]: PCH-5F 9.0 PCH-5F 5.0 PCH-5F 9.0      PCH-5F 7.0 PCH-5F 6.0 PCH-5F 5.0  PCH-7F 8.0 PCH-7F 5.0 PCH-7F 9.0      PCH-7F 7.0 PCH-7F 6.0 PCH-7F 5.0  CCP-20CF3 8.0 CCP-20CF3 8.0 CCP-20CF3      10.0 CCP-20CF3 5.0 CCP-20CF3 6.0 CCP-20CF3 6.0  CCP-30CF3 9.0 CCP-30CF3      9.0 CCP-30CF3 12.0 CCP-30CF3 6.0 CCP-30CF3 8.0 CCP-30CF3 9.0  CCP-50CF3      8.0 CCP-50CF3 9.0 CCP-50CF3 10.0 CCP-50CF3 6.0 CCP-50CF3 8.0 CCP-50CF3      9.0  ECCP-3F.F 11.0 ECCP-3F.F 11.0 ECCP-3F.F 11.0 ECCP-3F 8.0 ECCP-3F      6.0 ECCP-3F 8.0  ECCP-5F.F 10.0 ECCP-5F.F 10.0 ECCP-5F.F 10.0 ECCP-3F.F      11.0 ECCP-3F.F 11.0 ECCP-3F.F 10.0  CUP-3F.F 4.0 CUP-3F.F 5.0 CCP-30CF2.F      .F 9.0 ECCP-5F.F 11.0 ECCP-5F.F 11.0 ECCP-5F.F 11.0  CUP-5F.F 3.0      CUP-5F.F 4.0 CCP-50CF2.F.F 14.0 BCH-3F.F 4.0 CUP-3F.F 7.0 BCH-3F.F 4.0      CCP-30CF2.F.F 8.0 CCP-30CF2.F.F 8.0 CP-30CF3 3.0 BCH-5F.F 4.0 CUP-5F.F      6.0 BCH-5F.F 4.0  CCP-50CF2.F.F 14.0 CCP-50CF2.F.F 14.0 CP-50CF3 3.0      CUP-3F.F 6.0 CCP-30CF2.F.F 7.0 CUP-3F.F 6.0  CP-20CF3 .0 CP-20CF3 4.0      CUP-5F.F 5.0 CCP-50CF2.F.F 11.0 CUP-5F.F 6.0  CP-30CF3 4.0 CP-30CF3 4.0       CCP-30CF2.F.F 6.0 CBC-33F 3.0 CCP-30CF2.F.F 6.0  CP-50CF3 4.0 CP-50CF3      4.0   CCP-50CF2.F.F 6.0 CBC-53F 4.0 CCP-50CF2.F.F 6.0        CBC-33F 4.0        CBC-33F 2.0        CBC-53F 4.0   CBC-53F 3.0        example  225 226 227 228 229 230        Clearing Point [°C.]  +89  +103  +102  +99  +88  +99 Viscosity      [mm.sup.2 s.sup.-1 ]  ?  290  168 h  330  200  168 h? -20° C. d      · Δn (μm) = 0.5    870  96 <  1040  560       kr < 120      Δn (589 nm, 20° C.)  +0.0783  +0.0848  +0.0949  +0.0960      +0.0773  +0.0964 n.sub.e (589 nm, 20° C.)  1.5489  1.5559  1.5730       1.5751  1.5498  1.5767 Δε (1 kHz, 20° C.)  --      +6.9  --  +6.8  +5.3  -- .sup.ε ∥ (1 kHz, 20°      C.)  --  10.5  --  10.4  8.7  -- V.sub.(10,0,20) [V]  1.94  1.81  1.74      1.79  1.98  1.86 V.sub.(60,0,20) [V]  2.41  2.24  2.15  2.21  2.45  2.28      V.sub.(90,0,20) [V]  3.12  2.83  2.71  2.81  3.16  2.87 Composition [%]:      PCH-5F 9.0 PCH-5F 5.0 PCH-5F 4.0 PCH-5F 6.0 PCH-5F 7.0 PCH-5F 7.0      PCH-7F 10.0 PCH-7F 5.0 PCH-7F 5.0 PCH-7F 6.0 PCH-6F 6.0 PCH-7F 7.0      CCP20CF3 10.0 CCP-20CF3 8.0 CCP-20CF3 6.0 CCP-20CF3 6.0 PCH-7F 6.0      CCP-20CF3 5.0  CCP30CF3 11.0 CCP-30CF3 9.0 CCP-30CF3 7.0 CCP-30CF3 8.0      CCP-20CF3 8.0 CCP-30CF3 6.0  CCP-50CF3 10.0 CCP-50CF3 9.0 CCP-50CF3 8.0      CCP-50CF3 7.0 CCP-30CF3 10.0 CCP-50CF3 6.0  ECCP-3F.F 11.0 ECCP-3F.F      11.0 ECCP-3F 6.0 ECCP-3F.F 11.0 CCP-50CF3 10.0 ECCP-3F.F 15.0  ECCP-5F.F      10.0 ECCP-5F.F 10.0 ECCP-3F.F 10.0 ECCP-5F.F 11.0 ECCP-3F.F 14.0      ECCP-5F.F 14.0  CCP-30CF2.F.F 11.0 CUP-3F.F 5.0 ECCP-5F.F 10.0 BCH-3F.F      6.0 ECCP-5F.F 14.0 BCH-3F.F 4.0  CCP-50CF2.F.F 14.0 CUP-5F.F 4.0      CUP-3F.F 9.0 CUP-3F.F 7.0 CCP-30CF2.F.F 9.0 BCH-5F.F 4.0  CP-30CF3 4.0      CCP-30CF2.F.F 8.0 CUP5F.F 10.0 CUP-5F.F 6.0 CCP-50CF2.F.F 14.0 CUP-3F.F      6.0    CCP-50CF2.F.F 14.0 CCP-30CF2.F.F 7.0 CCP-30CF2.F.F 7.0 CP-30CF3      2.0 CUP-5F.F 5.0    CP-30CF3 6.0 CCP-50CF2.F.F 11.0 CCP-50CF2.F.F 11.0      CCP-30CF2.F.F 6.0    CP-50CF3 6.0 CBC-33F 3.0 CBC-33F 4.0   CCP-50CF2.F.F       6.0      CBC-53F 4.0 CBC-53F 4.0   CBC-33F 3.0            CBC-53F 3.0               CBC-55F 3.0        example 231 232 233 234 235 236        Clearing Point [°C.]  +86  +91  +93  +91  +89  -- Viscosity      [mm.sup.2 s.sup.-1 ] -20°       C.  --  --  --  200  --  -- d · Δn (μm) = 0.5      Δn (589 nm, 20° C.)  +0.0980  +0.0901  +0.0923  +0.0787      +0.0891  -- n.sub.e (589 nm, 20° C.)  1.5756  1.5614  1.5653      1.5503  1.5627  -- Δε (1 kHz, 20° C.)  +5.8  +5.2      +5.2  +5.6  +5.3  -- .sup.ε ∥ (1 kHz, 20° C.)      9.04  8.46  8.30  9.0  8.5  -- V.sub.(10,0,20) [V]  1.88  2.06?  2.04?      1.95  1.99?  -- V.sub.(60,0,20) [V]  2.22  2.42?  2.42?  2.42  2.35?  --      V.sub.(90,0,20) [V]  2.74  3.03?  3.02?  3.12  --  -- Composition [%]:      PCH-5F 8.5 PCH-5F 8.5 PCH-5F 8.5 PCH-5F 6.0 PCH-5F 8.5 PCH-5F 7.0      PCH-6F 6.8 PCH-6F 6.8 PCH-6F 6.8 PCH-6F 6.0 PCH-6F 6.8 PCH-7F 7.0      PCH-7F 5.1 PCH-7F 5.1 PCH-7F 5.1 PCH-7F 6.0 PCH-7F 5.1 CCP-20CF3 9.0      CCP-20CF3 6.8 CCP-20CF3 6.8 CCP-20CF3 6.8 CCP-20CF3 8.0 CCP-20CF3 6.8      CCP-30CF3 10.0  CCP-30CF3 10.2 CCP-30CF3 10.2 CCP-30CF3 10.2 CCP-30CF3      10.0 CCP-30CF3 10.2 CCP-50CF3 10.0  CCP-40CF3 6.0 CCP-40CF3 6.0 CCP-40CF3       6.0 CCP-50CF3 10.0 CCP-40CF3 6.0 ECCP-3F.F 12.0  CCP-50CF3 9.3 CCP-50CF3       9.3 CCP-50CF3 9.3 ECCP-3F.F 14.0 CCP-50CF3 9.3 ECCP-5F.F 11.0  BCH-3F.F      10.2 BCH-3F.F 10.2 BCH-3F.F 10.2 ECCP-5F.F 14.0 BCH-3F.F 10.2 CUP-3F.F      5.5  BCH-5F.F 8.5 BCH-5F.F 8.5 BCH-5F.F 8.5 CCP-30CF2.F.F 9.0 BCH-5F.F      8.5 CUP-5F.F 4.5  ECCP-30CF3 4.2 ECCP-30CF3 4.2 ECCP-30CF3 4.2 CCP-50CF2.      F.F 14.0 ECCP-30CF3 4.2 CCP-30CF2.F.F 9.0  ECCP-50CF3 4.2 ECCP-50CF3 4.2      ECCP-50CF3 4.2 CP-30CF3 3.0 ECCP-50CF3 4.2 CCP-50CF2.F.F 15.0  CBC-33F      1.7 CBC-33F 1.7 CBC-33F 1.7   CBC-33F 1.7  CBC-53F 1.7 CBC-53F 1.7      CBC-53F 1.7   CBC-53F 1.7  CBC-55F 1.7 CBC-55F 1.7 CBC-55F 1.7   CBC-55F      1.7  BCH-3F.F.F 15.0 CCP-30CF2.F.F 15.0 CCP-3CL.F.F 15.0   CCP-3F.F.F      15.0        example 237 238 239 240 241 242        Clearing Point [°C.]  +109  +108  +90  +89  +90  +91 Viscosity      [mm.sup.2 s.sup.-1 ]  --  --  --  --  --  280 -20°       C. d ·  Δn (μm) = 0.5 Δn (589 nm, 20°      C.)  +0.0870  +0.0866  +0.0821  +0.0818  +0.0797  +0.0787 n.sub.e (589      nm, 20° C.)  1.5622  1.5620  1.5542  1.5539  1.5513  1.5503      Δε (1 kHz, 20° C.)  --  --  --  --  --  5.85      .sup.ε ∥ (1 kHz, 20° C.)  --  --  --  --  --      9.34 V.sub.(10,0,20) [V]  --  1.97  1.69  1.68  1.76  1.80 V.sub.(60,0,20      ) [V]  --  2.41  2.09  2.05  2.17  2.21 V.sub.(90,0,20) [V]  --  2.99      2.61  2.57  2.70  2.75 Composition [%]: PCH-5F 6.0 PCH-5F 6.0 PCH-5F 8.0      PCH-5F 8.0 PCH-5F 9.0 PCH-5F 6.0  PCH-7F 6.0 PCH-7F 6.0 PCH-7F 8.0      PCH-6F 8.0 PCH-7F 9.0 PCH-7F 5.0  CCP-20CF3 8.0 CCP-20CF3 8.0 CCP-20CF3      8.0 CCP-20CF3 8.0 CCP20CF3 8.0 CCH-303 5.0  CCP-30CF3 9.0 CCP-30CF3 9.0      CCP-30CF3 9.0 CCP-30CF3 9.0 CCP-30CF3 9.0 CCH-501 4.0  CCP-50CF3 9.0      CCP-50CF3 9.0 CCP-50CF3 8.0 CCP-50CF3 8.0 CCP-50CF3 8.0 CCP-20CF3 6.0      ECCP-3F.F 11.0 ECCP-3F.F 11.0 ECCP-3F.F 11.0 ECCP-3F.F 11.0 ECCP-3F.F      12.0 CCP-30CF3 6.0  ECCP-5F.F 10.0 ECCP-5F.F 10.0 ECCP-5F.F 10.0      ECCP-5F.F 10.0 ECCP-5F.F 11.0 CCP-40CF3 6.0  CUP-3F.F 5.0 CP-3F.F 5.0      CUP03F.F 4.0 CUP-3F.F 4.0 CUP-3F.F 3.0 CCP-50CF3 6.0  CUP-5F.F 4.0      CUP-5F.F 4.0 CUP-5F.F 3.0 CUP-5F.F 3.0 CCP-30CF2.F.F 8.0 ECCP-3F.F 12.0      CCP-30CF2.F.F 8.0 CCP-30CF2.F.F 8.0 CCP-30CF2.F.F 8.0 CCP-30CF2.F.F 8.0      CCP-50CF2.F.F 14.0 ECCP-5F.F 12.0  CCP-50CF2.F.F 14.0 CCP-50CF2.F.F 14.0      CCP-50CF2.F.F 14.0 CCP-50CF2.F.F 14.0 CP-30CF3 5.0 CUP-3F.F 4.0      CCEPC-53 10.0 CCEPC-35 5.0 CP-30CF3 5.0 CP-30CF3 5.0 CP-50CF3 4.0      CCP-30CF2.F.F 12.0    CCEPC-53 5.0 CP-50CF3 4.0 CP-50CF3 4.0   CCP-50CF2.      F.F 12.0            CP-30CF3 4.0        example 243 244 245 246 247 248        Clearing Point [°C.]  +90  +89  +93  +107.2  +101  +94 Viscosity       [mm.sup.2 s.sup.-1 ]  --  --  --  --  --  -- -20°       C. d · Δn (μm) = 0.5 Δn (589 nm, 20° C.)       +0.0753  +0.0762  +0.1083  +0.0935  +0.1108  +0.0910 n.sub.e (589 nm,      20°       C.)  1.5467  1.5478  1.5954  1.5699  1.5985  1.5627 Δε (1      kHz, 20° C.)  --  --  --  --  --  -- .sup.ε ∥ (1      kHz, 20° C.)  --  --  --  --  --  -- V.sub.(10,0,20) [V]  1.97      1.96  1.80  1.88  1.87  -- V.sub.(60,0,20) [V]  2.43  2.42  2.22  2.33      2.29  -- V.sub.(90,0,20) [V]  3.05  3.04  2.86  2.94  2.95  -- Compositio      n [%] : PCH-5F 6.0 PCH-5F 8.0 PCH-5F 7.0 PCH-5F 6.0 PCH-5F 7.0 PCH-5F      5.0  PCH-7F 6.0 PCH-7F 8.0 PCH-6F 7.0 PCH-7F 6.0 PCH-6F 6.0 PCH-7F 5.0      CCH-303 6.0 CCH-303 7.0 PCH-7F 8.0 CCP-20CF3 8.0 PCH-7F 7.0 CCP-20CF3      9.0  CCH-501 5.0 CCP-20CF3 8.0 CCP-20CF3 5.0 CCP-30CF3 9.0 CCP-20CF3 5.0      CCP-30CF3 11.0  CCP-20CF3 6.0 CCP-30CF3 9.0 CCP-30CF3 6.0 CCP-50CF3 9.0      CCP-30CF3 6.0 CCP-40CF3 10.0  CCP-30CF3 6.0 CCP-50CF3 8.0 CCP-50CF3 6.0      ECCP-3F.F 11.0 CCP-50CF3 6.0 CCP-50CF3 11.0  CCP-40CF3 6.0 ECCP-3F.F      14.0 BCH-3F.F 12.0 ECCP-5F.F 10.0 BCH-3F.F 12.0 CUP-3F.F 11.0  CCP-50CF3      6.0 ECCP-5F.F 12.0 BCH-5F.F 12.0 CUP-3F.F 5.0 BCH-5F.F 6.0 CUP-5F.F 10.0       ECCP-3F.F 14.0 CCP-30CF2.F.F 7.0 CUP-3F.F 6.0 CUP-5F.F 4.0 CUP-3F.F 6.0      CCP-30CF2.F.F 12.0  ECCP-5F.F 12.0 CCP-50CF2.F.F 13.0 CUP-5F.F 5.0      CCP-30CF2.F.F 8.0 CUP-5F.F 5.0 CCP-50CF2.F.F 12.0  CCP-30CF2.F.F 12.0      CP-30CF3 3.0 CCP-30CF2.F.F 4.0 CCP-50CF2.F.F 14.0 CCP-30CF2.F.F 4.0      CCECP-5F.F 4.0  CCP-50CF2.F.F 12.0 CP-50CF3 3.0 CCP-50CF2.F.F 7.0      CBC-33F 5.0 CCP-50CF2.F.F 7.0  CP-30CF3 3.0   CBC-33F 4.0 CBC-53F 5.0      CBC-33F 4.0      CBC-53F 4.0   CBC-53F 4.0      CBC-55F 4.0   CBC-55F      3.0      CBC-33 3.0   CBC-33 3.0          CBC-53 3.0 

We claim:
 1. A liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, comprising:one or more compounds of formula I ##STR82## in which X is fluorine, chlorine, OCF₃ or OCHF₂, ring A is trans-1,4-cyclohexylene or 1,4-phenylene, and R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms; and one or more compounds selected from formula II ##STR83## one or more compounds selected from formula IV ##STR84## wherein R is as defined above, Q is --C₂ H₄ --, --C₄ H₈ -- or --CO--O, X' is F, Cl, CF₃ or OCHF₂, Y is H or F, A' is trans-1,4-cyclohexylene, and r is 0or
 1. 2. A medium according to claim 1, further comprising one or more compounds selected from formulae V and VI: ##STR85## wherein R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms; andZ is --C₂ H₄, --CO--O-- or --O--CO--.
 3. A medium according to claim 1, further comprising one or more compounds selected from formulae VII to XII: ##STR86## wherein R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms;X" is F, Cl, CF₃, OCF₃ or OCHF₂ ; Y is H or F; and r is 0 or
 1. 4. A medium according to claim 1, wherein the proportion of compounds of the formulae I, II, and IV together in the total mixture is at least 50% by weight.
 5. A medium according to claim 1, wherein the proportion of compounds of the formula I in the total mixture is from 10-50% by weight.
 6. A medium according to claim 1, wherein the proportion of compounds of formulae II and IV in the total mixture is 30-70% by weight.
 7. In an electrooptical liquid-crystal display device containing a liquid-crystalline medium, the improvement wherein said medium is one of claim
 1. 8. A medium according to claim 1, wherein X is chlorine, OCF₃ or OCHF₂.
 9. A medium according to claim 1, further comprising one or more compounds of formula A ##STR87## in which R is alkyl, oxaalkyl, fluoroalkyl or alkenyl in each case having up to 7 carbon atoms,X" is F, Cl, CF₃, OCF₃ or OCHF₂, Y is, in each case, H or F, and r is 0 or
 1. 10. A medium according to claim 9, wherein the X and two Y substituents in said compound of formula A are selected from one of the following groups (a)-(d):

    ______________________________________                                                  Y      X"           Y                                                 ______________________________________                                         (a)        F        F            H,                                            (b)        H        OCF.sub.3    H,                                            (c)        F        OCF.sub.3    H, or                                         (d)        F        OCHF.sub.2   H.                                            ______________________________________                                    


11. A medium according to claim 9, wherein ring A is cyclohexylene and X is OCHF₂ in formula I.
 12. A medium according to claim 9, wherein the compound of formula A is of the formula ##STR88## wherein (F) is F or H and n is 1 to
 7. 13. A medium according to claim 2, further comprising one or more compounds selected from formulae VII to XII: ##STR89## wherein R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms,X" is F, Cl, CF₃, OCF₃ or OCHF₂, Y is H or F, and r is 0 or
 1. 14. In a method of generating an electrooptical liquid crystal display using an electrooptical liquid crystal display device, the improvement wherein said device is one of claim
 7. 15. A medium according to claim 1, wherein Q is --C₂ H₄ -- or --C₄ H₈ --.
 16. A medium according to claim 1, further comprising one or more compounds of the formula ##STR90## wherein R is alkyl, alkoxy, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms, andY is H or F.
 17. A medium according to claim 13, wherein said medium consists essentially of compounds selected from formulae I, II, and IV-XII.
 18. A liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy comprising:one or more compounds of formula I ##STR91## and one or more compounds of formula A ##STR92## in which R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms, X is F, Cl, CF₃, OCF₃ or OCHF₂, ring A is trans-1,4-cyclohexylene or 1,4-phenylene, Y is, in each case, H or F, and r is 0 or
 1. 19. A medium according to claim 18, wherein the X and two Y substituents in said compound of formula A are selected from one of the following groups (a)-(d):

    ______________________________________                                                  Y      X            Y                                                 ______________________________________                                         (a)        F        F            H                                             (b)        H        OCF.sub.3    H,                                            (c)        F        OCF.sub.3    H, or                                         (d)        F        OCHF.sub.2   H.                                            ______________________________________                                    


20. A medium according to claim 18, wherein formula A is of the formula ##STR93## wherein (F) is F or H and n is 1 to
 7. 21. A liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, comprising:one or more compounds of formula I ##STR94## in which X is fluorine, chlorine, CF₃, OCF₃ or OCHF₂, ring A is trans-1,4-cyclohexylene or 1,4-phenylene, and R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms, and one or more compounds selected from formulae V and VI: ##STR95## wherein R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms, and Z is --C₂ H₄ --, --CO--O-- or --O--CO--.
 22. A liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, comprising:one or more compounds of formula I ##STR96## in which X is fluorine, chlorine, CF₃, OCF₃ or OCHF₂, ring A is trans-1,4-cyclohexylene or 1,4-phenylene, and R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms; and one or more compounds selected from formulae II, III and IV ##STR97## wherein R is as defined above; Q is --C₂ H₄ --, --C₄ H₈ -- or --CO--O; X is as defined above; Y is H or F; ring A is as defined above; and r is 0 or 1; further comprising one or more compounds selected from formulae V and VI: ##STR98## wherein R is as defined above; and Z is --C₂ H₄, --CO--O-- or --O--CO--; and further comprising one or more compounds selected from formulae VII to XII: ##STR99## wherein R, X, Y and r are as defined above.
 23. A medium according to claim 22, wherein said medium consists essentially of compounds selected from formulae I, II, and IV-XII. 